subsurface/Documentation/user-manual_fr.txt

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:toc:
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image::images/Subsurface4Banner.jpg["Banner", align="center"]

[big]#MANUEL UTILISATEUR#

*Auteurs du manuel* : Willem Ferguson, Jacco van Koll, Dirk Hohndel, Reinout Hoornweg,
Linus Torvalds, Miika Turkia, Amit Chaudhuri, Jan Schubert, Salvador Cuñat, Pedro Neves

[blue]#_Version 4.5, Octobre 2015_#


Bienvenue en tant qu'utilisateur de _Subsurface_, un programme avancé
d'enregistrement de plongées (carnet de plongées) avec une bonne
infrastructure pour décrire, organiser, interpréter et imprimer des plongées
en scaphandre et en apnée. _Subsurface_ offre de nombreux avantages par
rapport à d'autres solutions logicielles similaires :

 - Avez-vous besoin d'une façon d'enregistrer vos plongées utilisant des
   équipements loisirs, même sans utiliser d'ordinateur de plongée ?
 - Utilisez-vous deux marques différentes d'ordinateurs de plongée, chacun avec
   son propre logiciel propriétaire pour télécharger les enregistrements des
   plongées ? Plongez-vous avec un recycleur ou un équipement en circuit ouvert
   ou de loisir ? Utilisez-vous un enregistreur de profondeur et de durée
   Reefnet Sensus avec un ordinateur de plongée ? _Subsurface_ offre une
   interface standard pour télécharger les enregistrements des plongées à
   partir de tous ces équipements de plongée et pour enregistrer et analyser
   ces enregistrements dans un système unique.
 - Utilisez-vous plus d'un système d'exploitation ? _Subsurface_ est
   intégralement compatible avec Mac, Linux et Windows, ce qui vous permet
   d'accéder à vos enregistrements de plongées sur chaque système
   d'exploitation en utilisant une application unique.
 - Utilisez-vous Linux ou Mac et votre ordinateur de plongée n'a que des
   logiciels pour Windows pour télécharger les informations de plongées (par
   exemple Mares) ? _Subsurface_ fournit un moyen de télécharger et d'analyser
   vos enregistrements de plongées sur d'autres systèmes d'exploitation.
 - Avez-vous besoin d'un planificateur de plongée graphique intuitif qui
   intègre et prend en compte les plongées qui ont déjà été enregistrées ?
 - Do you need a way of storing or backing up your dive log on the Internet,
   allowing you to view your dive log from anywhere, using an Internet browser?

_Subsurface_ est disponible pour Windows (Win XP ou plus récent), les Macs
basés sur processeurs Intel (OS/X) et de nombreuses distributions
Linux. _Subsurface_ peut être compilé pour bien plus de plateformes
matérielles et d'environnements logiciels où Qt et libdivecomputer sont
disponibles.

Le but de ce document est l'utilisation du programme Subsurface. Pour
installer le logiciel, consultez la page _Téléchargement_ sur le
http://subsurface-divelog.org/[site web de _Subsurface_]. En cas de
problème, vous pouvez envoyer un e-mail sur
mailto:subsurface@subsurface-divelog.org[notre liste de diffusion] et
rapportez les bogues sur http://trac.hohndel.org[notre bugtracker].  Pour
des instructions de compilation du logiciel et (si besoin) de ses
dépendances, merci de consulter le fichier INSTALL inclus dans les sources
logicielles.

*Public* : Plongeurs loisirs, apnéistes, plongeurs Tek et plongeurs
professionnels

toc::[]

[[S_UserSurvey]]
Utilisation de ce manuel
------------------------
Lorsqu'il est ouvert depuis _Subsurface_, ce manuel n'a pas de contrôles
externes. Cependant, une fonction de _RECHERCHE_ est importante. Elle est
activée par la combinaison de touches du clavier Ctrl-F ou commande-F. Un
champ de recherche apparait en bas de la fenêtre. Il suffit de l'utiliser
pour rechercher n'importe quel terme dans le manuel.

Le sondage utilisateur
----------------------
Dans le but de développer _Subsurface_ d'une manière qui serve ses
utilisateurs de la meilleur manière qu'il soit, il est important d'avoir des
informations sur les utilisateurs. À l'ouverture de _Subsurface_ après avoir
utilisé le logiciel pendant une semaine environ, une fenêtre de sondage
apparait. Cela est complètement optionnel et l'utilisateur contrôle quelles
informations sont envoyées ou non à l'équipe de développement de
_Subsurface_. Toutes les données que l'utilisateur choisit d'envoyer sont
extrêmement utiles et ne seront utilisées que pour les futures
développements et modifications du logiciel pour coller au mieux aux besoins
des utilisateurs de _Subsurface_. Si vous complétez le sondage ou cliquez
sur l'option pour ne plus être sondé, cela devrait être la dernière
communication de ce type que vous recevrez. Cependant, si vos habitudes de
plongées ou d'utilisation de Subsurface changent, vous pouvez envoyer un
nouveau sondage en démarrant _Subsurface_ avec l'option  _--survey_ sur la
ligne de commande.

[[S_StartUsing]]
Commencer à utiliser le programme
---------------------------------

La fenêtre _Subsurface_ est généralement divisée en 4 panneaux avec un *Menu
principal* (Fichier Importer Journal Vue Aide) en haut de la fenêtre (pour
Windows et Linux) ou en haut de l'écran (pour Mac et Ubuntu Unity). Les
quatre panneaux sont :

La *liste des plongées* en bas à gauche, contenant une liste de toutes les
plongées du journal (carnet) de plongées de l'utilisateur. Une plongée peut
être sélectionnée et mise en surbrillance dans la liste en cliquant
dessus. Dans la plupart des cas, les touches haut/bas peuvent être utilisée
pour passer d'une plongée à l'autre. La *liste des plongées* est un outil
important pour manipuler un journal (carnet) de plongée.

La *carte de plongée* en bas à droite, affiche les sites de plongées de
l'utilisateur, sur une carte mondiale et centrée sur le site de la dernière
plongée sélectionnée dans la *liste des plongées*.

Les *informations* en haut à gauche, fournissent des informations détaillées
sur la plongée sélectionnée dans la *liste des plongées*, dont des
statistiques pour la plongée sélectionnée ou pour toutes les plongées mises
en surbrillance.

Le *profil de plongée* en haut à droite, affiche un profil de plongée
graphique de la plongée sélectionnée dans la *liste des plongées*.

Les séparateurs entre ces panneaux peuvent être déplacés pour modifier la
taille de chaque panneau. _Subsurface_ mémorise la position de ces
séparateurs, pour qu'au prochain lancement _Subsurface_ utilise ces
positions.

Si une unique plongée est sélectionnée dans la *liste des plongées*,
l'emplacement de la plongée, les informations détaillées et le profil de la
_plongée sélectionnée_ sont affichées dans les panneaux respectifs. D'autre
part, si plusieurs plongées sont sélectionnées, la dernière mise en
surbrillance est la _plongée sélectionnée_, mais les données de _toutes les
plongées mises en surbrillances_ sont affichées dans l'onglet *Stats* du
panneau *informations* (profondeur maximale, minimale et moyenne, les
durées, les températures de l'eau et le SAC (air consommé); temps total et
nombre de plongées sélectionnées).

[[S_ViewPanels]]

image::images/main_window_f22.jpg["The Main Window", align="center"]

L'utilisateur peut déterminer si lesquels des quatre panneaux sont affichés
en sélectionnant l'option *Vue* dans le menu principal. Cette fonctionnalité
permet plusieurs choix d'affichage :

*Tout* : affiche les quatre panneaux tels que sur la capture d'écran ci-dessus.

*Liste des plongées* : affiche uniquement la liste des plongées.

*Profil* : affiche uniquement le profile de plongée de la plongée sélectionnée.

*Info* : affiche uniquement les notes de plongées de la dernière plongée sélectionnée et les statistiques pour
toutes les plongées mises en surbrillance.

*Globe* : affiche uniquement la carte mondiale, centrée sur la dernière plongée sélectionnée.

Comme la plupart des autre fonctions qui peuvent être accédée via le menu
principal, ces options peuvent être utilisées par des raccourcis
clavier. Les raccourcis pour un système particulier sont affichés avec un
souligné des les entrées de menu. À cause des différents systèmes
d'exploitation et des divers langues, _Subsurface_ peut utiliser différentes
touches de raccourcis et ne sont donc pas détaillées ici.

Lorsque le programme est lancé pour la première fois, il n'affiche aucune
information. Ceci parce que le programme n'a aucune information de plongée
disponible. Dans les sections suivantes, le procédure pour créer a nouveau
carnet de plongée sera détaillée.

[[S_NewLogbook]]
Créer un nouveau carnet de plongée
----------------------------------
Sélectionner _Fichier -> Nouveau carnet de plongée_ à partir du menu
principal. Toutes les données de plongées sont effacées pour que de
nouvelles puissent être ajoutées. S'il existe des données non encore
enregistrées dans le carnet ouvert, l'utilisateur devra sélectionner s'il
faut les enregistrer ou non avant de créer le nouveau carnet.

[[S_GetInformation]]
== Enregistrement des informations de plongée dans le carnet

Maintenant qu'un nouveau carnet de plongée a été créé, il est simple de lui
ajouter des données. _Subsurface_ permet plusieurs façons pour ajouter des
données de plongée au carnet. Plus de détails dans les sections suivantes.

1) Si l'utilisateur possède un carnet manuscrit, un tableur ou une autre forme
   de
 carnet maintenu manuellement, les données de plongée peuvent être ajoutées
 au carnet en utilisant une des approches suivantes :

 - Entrer les informations de plongée à la main. Cela est utile si le plongeur
   n'a pas
 utilisé d'ordinateur de plongée et que les plongées sont inscrites dans un
 carnet manuscrit. Voir  xref:S_EnterData[Entrer les informations de plongée
 à la main]

 - Importer les informations de plongée qui ont été maintenues soit dans un
   tableur
 soit dans un fichier CSV. Se reporter à : xref:S_Appendix_D[ANNEXE D :
 Exporter un tableur vers le format CSV] et à
 xref:S_ImportingCSVDives[Importer des plongées au format CSV].

2) Si les plongées ont été enregistrées en utilisant un ordinateur de plongée,
   le profil de profondeur de la
 plongée et de nombreuses informations supplémentaires peuvent être
 utilisées. Ces plongées peuvent être importées à partir de :

 - L'ordinateur de plongée lui-même. Voir : xref:S_ImportDiveComputer[Importer
   de nouvelles informations de plongée à partir de l'ordinateur de plongée] ou

 - Logiciels propriétaires fournis par les fabricants d'ordinateurs de
   plongée. Voir
 xref:S_ImportingAlienDiveLogs[Importer les informations à partir d'autres
 sources de données numériques ou d'autres formats de données].

 - Importer à partir d'un tableur ou de fichiers CSV contenant les profils de
   plongées.
 Voir : xref:S_ImportingCSVDives[Importer les plongées au format CSV à partir
 des ordinateurs de plongées ou d'autres logiciels de carnet de plongée]


[[S_EnterData]]
=== Entrer les informations de plongée à la main

This is usually the approach for dives without a dive computer. The basic
record of information within _Subsurface_ is a dive. The most important
information in a simple dive logbook usually includes dive type, date, time,
duration, depth, the names of your dive buddy and of the dive master or dive
guide, and some remarks about the dive. _Subsurface_ can store much more
information than this for each dive. In order to add a dive to a dive log,
select _Log -> Add Dive_ from the Main Menu. The program then shows three
panels to enter information for a dive: two tabs in the *Info* panel
(*Notes* and *Equipment*), as well as the *Dive Profile* panel that displays
a graphical profile of each dive. These panels are respectively marked
[red]#A#, [red]#B# and [red]#C# in the figure below. Each of these tabs will
now be explained for data entry.

image::images/AddDive1_f22.jpg["FIGURE: Add dive", align="center"]

When one edits a field in Notes or Equipment panels, _Subsurface_ enters
*Editing Mode*, indicated by the message in the blue box at the top of the
*Notes* panel (see the image below). This message is displayed in all the
panels under Notes and Equipment when in *Editing Mode*.

image::images/BlueEditBar_f22.jpg["Blue edit bar", align="center"]

The _Apply changes_ button should only be selected after all the parts of a
dive have been entered.  When entering dives by hand, the _Info_,
_Equipment_ and _Profile_ tabs should be completed before saving the
information. By selecting the _Apply changes_ button, a local copy of the
information for this specific dive is saved in memory. When one closes
Subsurface, the program will ask again, this time whether the complete dive
log should be saved on disk or not.

[[S_CreateProfile]]
==== Creating a Dive Profile

The *Dive Profile* (a graphical representation of the depth of the dive as a
function of time) is indicated in the panel on the top right hand of the
_Subsurface_ window. When a dive is manually added to a logbook,
_Subsurface_ presents a default dive profile that needs to be modified to
best represent the dive being described:

image::images/DiveProfile1_f20.jpg["FIGURE: Initial dive profile", align="center"]

_Modifying the dive profile_: When the cursor is moved around the dive
profile, its position is indicated by two right-angled red lines as shown
below.  The time and depth represented by the cursor are indicated at the
top of the black information box (@ and D). The units (metric/imperial) on
the axes are determined by the *Preference* settings. The dive profile
itself comprises several line segments demarcated by waypoints (white dots
on the profile, as shown above). The default dive depth is 15 m.  If the
dive depth was 20 m then the user needs to drag the appropriate waypoints
downwards to represent 20 m. To add a waypoint, double-click on any line
segment. To move an additional waypoint, drag it.  To remove this waypoint,
right-click on it and choose "Remove this point" from the context menu. Drag
the waypoints to represent an accurate time duration for the dive. Below is
a dive profile for a dive to 20 m for 30 min, followed by a 5 minute safety
stop at 5 m.

image::images/DiveProfile2_f20.jpg["FIGURE: Edited dive profile", align="center"]

_Specifying the gas composition:_ The gas composition used is clearly
indicated along the line segments of the dive profile. This defaults to the
first gas mixture specified in the *Equipment* tab, which was air in the
case of the profile above. The gas mixtures of segments of the dive profile
can be edited. This is done by right-clicking on the particular waypoint and
selecting the appropriate gas from the context menu. Changing the gas for a
waypoint affects the gas shown in the segment _to the left_ of that
waypoint. Note that only the gases defined in the *Equipment* tab appear in
the context menu (see image below).

image::images/DiveProfile3_f20.jpg["FIGURE: Gas composition context menu", align="center"]

With the profile having been defined, more details must be added in order to
have a fuller record of the dive. To do this, the *Notes* and the
*Equipment* tabs on the top left hand of the _Subsurface_ window should be
used. Click on xref:S_Notes_dc[*this link*] for instructions to use these
tabs.

[[S_ImportDiveComputer]]
=== Importer de nouvelles informations de plongée à partir de l'ordinateur de plongée

==== Connecting and importing data from a dive computer.

The use of dive computers allows the collection of a large amount of
information about each dive, e.g. a detailed record of depth, duration,
rates of ascent/descent and of gas partial pressures. _Subsurface_ can
capture this information and present it as part of the dive information,
using dive information from a wide range of dive computers. The latest list
of supported dive computers can be found at:
link:http://subsurface-divelog.org/documentation/supported-dive-computers/[
Supported dive computers].

[icon="images/icons/warning2.png"]
[WARNING]
Several dive computers consume more power when they are in their
PC-Communication mode. **This could drain the dive computer's battery**. We
therefore recommend that the user checks if the dive computer is charged
when connected to the USB port of a PC. For example, several Suunto and
Mares dive computers do not recharge through the USB connection. Users
should refer to the dive computer's manual if they are unsure whether the
dive computer recharges its batteries while connected to the USB port.

To import dive information from a dive computer to a computer with
_Subsurface_, it is necessary that the two pieces of equipment communicate
with one another.  This involves setting up the communications port (or
mount point) of the computer with _Subsurface_ that communicates with the
dive computer. In order to set up this communication, one needs to find the
appropriate information to instruct _Subsurface_ where and how to import the
dive information.
xref:_appendix_a_operating_system_specific_information_for_importing_dive_information_from_a_dive_computer[Appendix
A] provides the technical information to help the user achieving this for
different operating systems and
xref:_appendix_b_dive_computer_specific_information_for_importing_dive_information[Appendix
B] has dive computer specific information.

After this, the dive computer can be hooked up to the user's PC, which can
be achieved by following these steps:

1. The interface cable should be connected to a free USB port (or the Infra-red
	or Bluetooth connection set up as described later in this manual)

2. The dive computer should be placed into PC Communication mode.
	(Se reporter au manuel de l'ordinateur de plongée)

3. In _Subsurface_, from the Main Menu, select _Import -> Import From Dive
   Computer_.  Dialogue *A* in the figure below appears:


image::images/DC_import_f20.jpg["FIGURE: Download dialogue 1", align="center"]

Dive computers tend to keep a certain number of dives in their memory, even
though these dives have already been imported to _Subsurface_. For that
reason, if the divecomputer allows this, _Subsurface_ only imports dives
that have not been uploaded before. This makes the download process faster
on most dive computers and also saves battery power of the dive computer (at
least for those not charging while connected via USB).

 - The dialogue has two drop-down lists, *Vendor* and *Dive Computer*. On the
   *vendor* drop-down list select the make of the computer, e.g.  Suunto,
   Oceanic, Uwatec, Mares. On the *Dive Computer* drop-down list, the model
   name of the dive computer must be selected, e.g. D4 (Suunto), Veo200
   (Oceanic), or Puck (Mares).

 - The *Device or Mount Point* drop-down list contains the USB or Bluetooth
   port name that _Subsurface_ needs in order to communicate with the dive
   computer.  The appropriate port name must be selected. Consult
   xref:_appendix_a_operating_system_specific_information_for_importing_dive_information_from_a_dive_computer[Appendix
   A] and
   xref:_appendix_b_dive_computer_specific_information_for_importing_dive_information[Appendix
   B] for technical details on how to find the appropriate port information for
   a particular dive computer and, in some cases, how to do the correct
   settings to the operating system of the computer on which _Subsurface_ is
   running.

 - If all the dives on the dive computer need to be downloaded, check the
   checkbox _Force download of all dives_. Normally, _Subsurface_ only
   downloads dives after the date-time of the last dive in the *Dive List*
   panel. If one or more of your dives in _Subsurface_ have been accidentally
   deleted or if there are older dives that still need to be downloaded from
   the dive computer, this checkbox needs to be activated. Some dive computers
   (e.g. Mares Puck) do not provide a contents list to _Subsurface_ before the
   download in order to select only new dives.  Consequently, for these dive
   computers, all dives are downloaded irrespective of the status of this check
   box.

 - If the checkbox _Always prefer downloaded dives_ has been checked and,
   during download, dives with identical date-times exist on the dive computer
   and on the _Subsurface_ *Dive List* panel, the dive in the _Subsurface_
   divelog will be overwritten by the dive record from the dive computer.

 - The checkbox marked _Download into new trip_ ensures that, after upload, the
   downloaded dives are grouped together as a new trip(s) in the *Dive List*.

 - Do *not* check the checkboxes labelled _Save libdivecomputer logfile_ and
   _Save libdivecomputer dumpfile_. These are only used as diagnostic tools
   when problems with downloads are experienced (see below).

 - Then select the _Download_ button.  With communication established, one can
   see how the data are retrieved from the dive computer.  Depending on the
   make of the dive computer and/or number of recorded dives, this could take
   some time. Be patient. The _Download_ dialogue shows a progress bar at the
   bottom of the dialogue (for some dive computers the progress information
   could be inaccurate as we cannot determine how much downloadable data there
   is until all data have been downloaded). After successful download, Dialogue
   *B* in the figure above appears.  After the dives have been downloaded, they
   appear in a tabular format on the righthand side of the dialogue (see image
   *B*, above). Each dive comprises a row in the table, with the date, duration
   and depth shown. Next to each dive is a checkbox: check all the dives that
   need to be transfered to the *Dive List*. In the case of the image above,
   the last six dives are checked and will be transfered to the *Dive
   List*. Then click the _OK_ button at the bottom of the dialogue. All the
   imported dives appear in the *Dive List*, sorted by date and
   time. Disconnect and switch off the dive computer to conserve its battery
   power.



After this has been completed, select the OK button.  The checked dives are
transfered to the *Dive List*.

 - If there is a problem in communicating with the dive computer, an error
   message will be shown, similar to this text: "Unable to open /dev/ttyUSB0
   Mares (Puck Pro)". Refer to the text in the box below.


****
*PROBLEMS WITH DATA DOWNLOAD FROM A DIVE COMPUTER?*
[icon="images/icons/important.png"]
[IMPORTANT]
Check the following:

 - Is the dive computer still in PC-communication or Upload mode?

 - Is the battery of the dive computer fully charged? If not then the battery
   must be charged or replaced.

 - Is the connecting cable faulty? Does the cable work perfectly using other
   software? Has it worked before, or is this the first time the cable is being
   used? Are the contacts on the dive computer and the cable clean?

 - Consult
   xref:_appendix_a_operating_system_specific_information_for_importing_dive_information_from_a_dive_computer[Appendix
   A] and make sure that the correct Mount Point was specified (see above).

 - On Unix-like operating systems, does the user have write permission to the
   USB port? If not, consult
   xref:_appendix_a_operating_system_specific_information_for_importing_dive_information_from_a_dive_computer[Appendix
   A]

If the _Subsurface_ computer does not recognise the USB adaptor by showing
an appropriate device name next to the Mount Point, then there is a
possibility that the cable or USB adaptor is faulty. A faulty cable is the
most common cause of communication failure between dive computer and
_Subsurface_ computer. It is also possible that the _Subsurface_ computer
cannot interpret the data. Perform a download for diagnostic purposes with
the following two check boxes checked in the download dialogue discussed
above:

	Save libdivecomputer logfile
	Save libdivecomputer dumpfile

*Important*: These check boxes are only used when problems are encountered
during the download process: under normal circumstances they should not be checked.
When checking these boxes, the user is prompted to select a folder to
save the information to. The default folder is the one in which the _Subsurface_
dive log is kept.

*Important:* _After downloading with the above checkboxes
checked, no dives are added to the
*Dive List* but two files are created in the folder selected above_:

	subsurface.log
	subsurface.bin

These files should be send to the _Subsurface_ mail list:
_subsurface@subsurface-divelog.org_ with a request for the files to be
analysed. Provide the dive computer make and model as well as contextual
information about the dives recorded on the dive computer.
****

[[S_DeviceNames]]
==== Changing the name of a dive computer

It may be necessary to distinguish between different dive computers used to
upload dive logs to _Subsurface_. For instance if one's partner's dive
computer is the same make and model as one's own and dive logs are uploaded
from both dive computers to the same _Subsurface_ computer, then one would
perhaps like to call one dc "Alice's Suunto D4" and the other one "Bob's
Suunto D4". Alternatively, consider a technical diver dives with two or more
dive computers of the same model, the logs of both (or all) being uploaded.
In this case it might be prudent to call one of them "Suunto D4 (1)" and
another one "Suunto D4 (2)". This is easily done in _Subsurface_.  On the
*Main Menu*, select _Log -> Edit device names_. A dialog opens, indicating
the current Model, ID and Nickname of the dive computers used for
upload. Edit the Nickname field for the appropriate dive computer. After
saving the Nickname, the dive logs show the nickname for that particular
device instead of the model name, allowing easy identification of devices.

[[S_EditDiveInfo]]
==== Updating the dive information imported from the dive computer.

With the uploaded dives in the *Dive List*, the information from the dive
computer is not complete and more details must be added in order to have a
fuller record of the dives. To do this, the *Notes* and the *Equipment* tabs
on the top left hand of the _Subsurface_ window should be used.

[[S_Notes_dc]]
===== Notes

To have a more complete dive record the user needs to add additional
information by hand. The procedure below is virtually identical for
hand-entered dives and for dives downloaded from a dive computer.

In some cases, one has to provide the date and time of the dive, e.g. when
entering a dive by hand or when a dive computer does not privide the date
and time of the dive.  (Usually the date and time of the dive, gas mixture
and water temperature are shown as obtained from the dive computer)  If the
contents of the *Notes tab* is changed or edited in any way, the message in
a blue box at the top of the panel indicates that the dive is being
edited. If one clicks on the *Notes* tab, the following fields are visible
(left hand image, below):

image::images/AddDive3_f22.jpg["FIGURE: The Notes tab", align="center"]

The right hand image, above, shows a *Notes tab* filled with dive
information.  The *Time* field reflects the date and time of the dive. By
clicking the date, a calendar is displayed from which one can choose the
correct date. Press ESC to close the calendar.  The time values (hour and
minutes) can also be edited directly by clicking on each of them in the text
box and by overtyping the information displayed.

*Air/water temperatures*: Air and water temperatures during the dive are shown
in text boxes to the right of the Start time. Many dive computers supply water
temperature information and this box may therefore contain information.
If air temperature is not provided by the dive computer, the first temperature reading
might be used for the air temperature. Generally this is close enough to the real air temperature as
the change in the temperature sensor reading is quite slow to follow the changes in the environment.
If editing is required, only a value is required, the units of temperature will be
automatically supplied by
_Subsurface_ (following the _Preferences_, metric or imperial units will
be used).

*Location*: Here the name of the dive site can be entered, e.g. "Tihany, Lake
Balaton, Hungary". Dive locations are managed as a separate part of the dive log.
After entering the information for a particilar dive site, and several dives are
performed at the same location, the information is re-used without requiring
full dive site information again. Existing dive location information
can be edited at any time by selecting (on the *Dive List* panel) a dive performed at that site
and by opening the location information by clicking the globe button on the
right of the location name (see image on the righ, above). When entering a dive location name, auto location of
dive site names makes it easy to select a dive site that already exists in the dive log
(i.e. when typing the name of a dive site,
a dropdown list appears showing all sites with similar names). If the dive
site has been used before, click on the already-existing name.

If the present dive site has not been used before, a message appears as
follows (image *A* below):

image::images/Locations1_f22.jpg["FIGURE:Location description panel", align="center"]

Click the + icon on the right hand side. A panel appears to enter the
coordinates and other important information about the site (image *B*,
above). The most important items are the coordinates of the site. There are
three ways of specifying the coordinates:

a. One can find the coordinates on the world map in the bottom right hand part
   of the Subsurface window. The map displays an orange bar indicating "No
   location data - Move the map and double-click to set the dive
   location". Upon a double-click at the appropriate place, the orange bar
   disappears and the coordinates are stored.

b. The coordinates can be obtained from the _Subsurface_ Companion app if the
   user has an Android or iPhone device with GPS and if the coordinates of the
   dive site were stored using that device.  xref:S_Companion[Click here for
   more information]

c. The coordinates can be entered by hand if they are known, using one of four
   formats with latitude followed by longitude:

	ISO 6709 Annex D format e.g. 30°13'28.9"N 30°49'1.5"E Degrees and decimal
	minutes, e.g. N30° 13.49760' , E30° 49.30788' Degrees minutes seconds,
	e.g. N30° 13' 29.8" , E30° 49' 1.5" Decimal degrees, e.g. 30.22496 ,
	30.821798

Southern hemisphere latitudes are given with a *S*, e.g. S30°, or with a
negative value, e.g. -30.22496. Similarly western longitudes are given with
a *W*, e.g. W07°, or with a negative value, e.g. -7.34323. Some keyboards
don't have the degree sign (°). It can be replaced by a *d* like this: N30d
W20d.

*Important*: GPS coordinates of a dive site are linked to the Location
name - so adding coordinates to dives that do not have a location description
will cause unexpected behaviour (Subsurface will think that all of these
dives have the same location and try to keep their GPS coordinates the
same).

Enter any other textual information about the dive site (Description and
Notes), then select _Apply Changes_ to save the geolocation for this dive
site. At a later stage the dive site information can be edited by clicking
the globe icon to the right of the dive site name in the *Notes tab*.

*Dive mode*: This is a dropdown box allowing one to choose the type of dive
performed. The options are OC (Open Circuit SCUBA, the default seting, meant for most recreational dives),
Freedive (dive without SCUBA equipment), CCR (Closed-circuit
rebreather) and pSCR (Passive semi-closed rebreather).

*Divemaster*: The name of the dive master or dive guide for this dive should be
entered in this field
which offers auto selection based on the list of dive masters in
the current logbook.

*Buddy*: In this field, one enters the name(s) of the buddy / buddies
(separated with commas) who accompanied him/her on the
dive. Auto selection based on the list of buddies in the current logbook is
offered.

*Suit*: Here the type of dive suit used can be entered.
Auto selection of the suit description is available.
Some dry-suit users may choose to use this field to record what combination of
suit and thermal undersuit was used.

*Rating*: One can provide a subjective overall rating of the dive on a
5-point scale by clicking the appropriate star on the rating scale.

*Visibility*: Similarly, one can provide a rating of visibility during the
dive on a
5-point scale by clicking the appropriate star.

*Tags*: Tags that describe the type of dive performed can be entered
here (separated by commas). Examples of common tags are boat, drift, training,
cave, etc.
_Subsurface_ has many built-in tags. If the user starts typing a tag, the
program
will list the tags that correspond to the typing. For instance, if the user
typed
+cav+, then the tags *cave* and *cavern* are shown for the user to choose from.

*Notes*: Any additional information for the dive can be entered here.

The _Apply changes_ and _Discard changes_ buttons are used to save all the
information for tabs in the *Info* panel and in the *Dive Profile* panel, so
there's no need to use them until *ALL* other information has been
added. The image xref:S_Notes_dc[at the beginning of this section] shows an
example of a *Notes tab* after completion of the dive information.

===== Equipment

The Equipment tab allows one to enter information about the type of cylinder
and gas used as well as the weights used for the dive. The message in a blue
box at the top of the panel:

image::images/BlueEditBar_f22.jpg["FIGURE: Blue edit bar", align="center"]

indicates that the dive is being edited. This is a highly interactive part
of _Subsurface_ and the information on cylinders and gases (entered here)
determines the behaviour of the *Dive profile* (top right-hand panel).

[[cylinder_definitions]]
*Cylinders*: The cylinder information is entered through a dialogue that looks
like this:

image::images/DC_gas-dialogue1_f20.jpg["FIGURE: Initial cylinder dialogue", align="center"]

For hand-entered dives, this information needs to be typed in. For dive
computers, _Subsurface_ often obtains the gas used from the dive computer
and automatically inserts the gas composition(% oxygen or % helium) in the
table. The + button at the top right allows the user to add more cylinders
for this dive. The dark dustbin icon on the left allows the deletion of
information for a cylinder.  Note that it is not possible to delete a
cylinder if it is used during the dive. A cylinder might be implicitly used
in the dive, even without a gas change event.

The user should start by selecting a cylinder type on the left-hand side of
the table.  To select a cylinder, the _Type_ box should be clicked. This
brings up a list button that can be used to display a dropdown list of
cylinders:

image::images/DC_gas-dialogue2_f20.jpg["FIGURE: The cylinder drop-down list button", align="center"]

The drop-down list can then be used to select the cylinder type that was
used for this dive or the user may start typing in the box which shows the
available options for the entered characters. The *Size* of the cylinder as
well as its working pressure (_Work.press_) will automatically be shown in
the dialogue.

Next, indicate the starting pressure and the ending pressure of the
specified gas during the dive. The unit of pressure (metric/imperial)
corresponds to the settings chosen in the _Preferences_.

Finally, provide the gas mixture used. If air was used, the value of 21% can
be entered or this field can be left blank. If nitrox or trimix were used,
their percentages of oxygen and/or helium should be entered.  Any
inappropriate fields should be left empty. After typing the information for
the cylinder, save the data either by pressing _ENTER_ on the keyboard or by
clicking outside the cell containing the cursor. Information for any
additional cylinders can be added by using the + button at the top right
hand. Following is an example of a complete description for a dive using two
cylinders (air and EAN50):

image::images/CylinderDataEntry3_f20.jpg["FIGURE: a completed cylinder dive information table", align="center"]

*Weights*: Information about the weight system used can be entered
using a dialogue very similar to that of the cylinder information. If one
clicks
the + button on the top right of the weights dialogue, the table looks like
this:

image::images/WeightsDataEntry1_f20.jpg["FIGURE:The Weights dialogue", align="center"]

By clicking on the _Type_ field, a drop-down list becomes accessible through
a down-arrow:

image::images/WeightsDataEntry2_f20.jpg["FIGURE:Weights type drop-down list button", align="center"]
This can be used to select the type of weight system used during the dive or
the user may start typing in the box to specify a different weighting
mechanism that will be saved by _Subsurface_.  In the *Weight* field, type
in the amount of weight used during the dive. After specifying the weight
system, save the data by either pressing _ENTER_ on the keyboard or by
clicking outside the cell with the cursor.  It is possible to enter
information for more than one weight system by adding an additional system
using the + button on the top right hand. Weight systems can be deleted
using the dustbin icon on the left hand. Here is an example of information
for a dive with two types of weights: integrated as well as a weight belt:

image::images/WeightsDataEntry3_f20.jpg["FIGURE: A completed weights information table", align="center"]

==== Editing several selected dives simultaneously

_METHOD 1_: After uploading dives from a dive computer, the dive profiles of
each uploaded dive is shown in the *Dive profile* tab, as well as a few
items of information in the *Notes* tab (e.g. water temperature) and in the
*Equipment* tab (e.g. gas pressures and gas composition). However the other
fields remain empty.  It may be useful to simultaneously edit some of the
fields in the *Notes* and *Equipment* tabs.  For instance, it is possible
that a diver performed several dives during a single day, using identical
equipment while diving at the same dive site or with the same dive master
and/or buddy or tags. Instead of completing the information for each of
these dives separately, one can select all the dives for that day in the
*Dive List* and insert the same information in the *Notes* and *Equipment*
fields that need identical information. This is achieved by editing the dive
notes or the equipment for any one of the selected dives.

The simultaneous editing only works with fields that do not already contain
information.  This means that, if some fields have been edited for a
particular dive among the selected dives, these are not changed while
editing the dives simultaneously. Technically, the rule for editing several
dives simultaneously is: if the data field being edited contains _exactly
the same information_ for all the dives that have been selected, the new,
edited information is substituted for all the selected dives, otherwise only
the edited dive is changed, even though several dives have been selected in
the *Dive List*. This greatly speeds up the completion of the dive log after
several similar dives.

[[S_CopyComponents]]
_METHOD 2_:There is a different way of achieving the same goal. Select a
dive with all the appropriate information typed into the *Notes* and
*Equipment* tabs. Then, from the main menu, select _Log -> Copy dive
components_.  A box is presented with a selection of check boxes for most of
the fields in the *Notes* and *Equipment* tabs.  Select the fields to be
copied from the currently selected dive, then select _OK_. Now, in the *Dive
List*, select the dives into which this information is to be pasted. Then,
from the main menu, select _Log -> Paste dive components_.  All the selected
dives now contain the data initially selected in the original source dive
log.

==== Adding Bookmarks to a dive

Many divers wish to annotate their dives with text that indicate particular
events during the dive, e.g. "Saw dolphins", or "Released surface
buoy". This is easily done:

 - Right-click at the appropriate point on the dive profile.  This brings up
   the dive profile context menu. Select _Add bookmark_. A red flag is placed
   on the dive profile at the point that was initially selected (see *A*
   below).

 - Right-click on the red flag. This brings up the context menu (see *B*
   below). Select _Edit name_.

 - A text box is shown. Type the explanatory text for the bookmark (see *C*
   below). Select _OK_.  This saves the text associated with the bookmark.

 - If one hovers using the mouse over the red bookmark, the appropriate text is
   shown at the bottom of the information box (see *D* below).

image::images/Bookmarks.jpg["FIGURE: Bookmark dialog", align="center"]


==== Saving the updated dive information

The information entered in the *Notes* tab and the *Equipment* tab can be
saved by using the two buttons on the top right hand of the *Notes* tab. If
the _Apply changes_ button is clicked, the dive data are saved in the memory
image of the dive. If the _Discard changes_ button is clicked, then the
newly entered dive data are erased from the computer memory, although the
dive profile is retained. When the user exits _Subsurface_ there is a final
prompt to confirm that the new data should now be saved permanently on the
computer disk.

=== Importer les informations à partir d'autres sources de données numériques ou d'autres formats de données

[[S_ImportingAlienDiveLogs]]

If a user has been diving for some time, it is possible that several dives
were logged using other dive log software. This information does not need
retyping because these dive logs can probably be imported into
_Subsurface_. _Subsurface_ will import dive logs from a range of other dive
log software. While some software is supported natively, for others the user
has to export the logbook(s) to an intermediate format so that they can then
be imported by _Subsurface_.  Currently, _Subsurface_ supports importing CSV
log files from several sources.  APD LogViewer, XP5, Sensus and Seabear
files are preconfigured, but because the import is flexible, users can
configure their own imports.  Manually kept log files (e.g. a spreadsheet)
can also be imported by configuring the CSV import.  _Subsurface_ can also
import UDDF and UDCF files used by some divelog software and some dive
computers, like the Heinrichs & Weikamp DR5. Finally, for some divelog
software like Mares Dive Organiser it is currently suggested to import the
logbooks first into a webservice like _divelogs.de_ and then import them
from there with _Subsurface_, as divelogs.de supports a few additional
logbook formats that _Subsurface_ currently cannot parse.

If the format of other software is supported natively on Subsurface, it
should be sufficient to select either _Import -> Import log files_ or _File
-> Open log file_. _Subsurface_ supports the data formats of many dive
computers, including Suunto and Shearwater. When importing dives,
_Subsurface_ tries to detect multiple records for the same dive and merges
the information as best as it can. If there are no time zone issues (or
other reasons that would cause the beginning time of the dives to be
significantly different) _Subsurface_ will not create duplicate
entries. Below follows more specific information to achieve data import to
_Subsurface_.

==== Using the universal import dialogue
[[Unified_import]]

Importing dives from other software is performed through a universal
interface activated by selecting _Import_ from the Main Menu, then clicking
on _Import Log Files_. This brings up dialogue *A*, below.

image::images/Import1_f20.jpg["FIGURE: Import dialogue: step 1", align="center"]

Towards the bottom right is a dropdown selector with a default label of
_Dive Log Files_ which gives access to the different types of direct imports
available, as in dialogue *B*, above. Currently these are:

 - XML-formatted dive logs (DivingLog 5.0, MacDive and several other dive log
   systems)
 - Cochran dive logs
 - UDDF-formatted dive logs (e.g. Kenozoooid)
 - UDCF-formatted dive logs
 - Poseidon MkVI CCR logs
 - APD Inspiration/Evolution CCR logs
 - LiquiVision logs
 - divelog.de logs
 - OSTC Tools logs
 - JDiveLog
 - Suunto Dive Manager (DM3 and DM4)
 - CSV (text-based and spreadsheet-based) dive logs, including APD CCR logs

Selecting the appropriate format and then the specific log file in the large
window containing the file list on the right of the dialogue opens the
imported dive log in the _Subsurface_ *Dive List*. Some other formats, not
accessible through the Import dialogue are also supported, as explained
below.

==== Importing from  OSTCTools

_OSTC Tools_ is a Microsoft-based suite of dive download and dive management
tools for the OSTC family of dive computers. _OSTC Tools_ downloads dive
data from the dive computer and stores it as a binary file with file
extension _.dive_ . Subsurface can directly import these files when using
the universal import dialogue. From the dropdown list at the bottom right
select _OSTCTools Files (.dive .DIVE)_. This makes the _OSTC Tools_ dive
logs visible in the file list panel. Select one or more dive, then click the
_Open_ button. The OSTC dives are shown in the *Dive List* panel.

Actually, all H&W devices supported by OSTCTools can be imported to
_Subsurface_, this includes OSTC, OSTC Mk2, OSTC 2N/2C, OSTC3, OSTC Sport,
and probably although untested, Frog, OSTC2 and OSTC CR.

Please, remember that OSTCTools is *not* a true diving log software, but a
useful set of tools for analysis and management of OSTC devices. This way,
only raw dive computer data will be performed with the import to
_Subsurface_; one has to to manually complete the rest of data which may be
important (buddies, equipment, notes, etc).


==== Importing from Mares Dive Organiser V2.1

Since Mares utilise proprietary Windows software not compatible with
multi-platform applications, these dive logs cannot be directly imported
into _Subsurface_. Mares dive logs need to be imported using a three-step
process, using _www.divelogs.de_ as a mechanism to extract the dive log
information.

1. Export the dive log data from Mares Dive Organiser to the user's desktop,
   using a _.sdf_ file name extension. Refer to xref:Mares_Export[Appendix C]
   for more information.
2. Data should then be imported into _www.divelogs.de_. One needs to create a
   user account in _www.divelogs.de_, log into that web site, then select
   _Import Logbook -> Dive Organiser_ from the menu on the left hand side.  The
   instructions must be carefully followed to transfer the dive information (in
   _.sdf_ format) from the Dive Organiser database to _www.divelogs.de_.
3. Finally, import the dives from _divelogs.de_ to _Subsurface_, using the
   instructions below.


[[S_ImportingDivelogsDe]]
==== Importing dives from *divelogs.de*

The import of dive information from _divelogs.de_ is simple, using a single
dialogue box. The _Import -> Import from Divelogs.de_ option should be
selected from the Main Menu. This brings up a dialogue box (see image *A*
below). Enter a user-ID and password for _divelogs.de_ into the appropriate
fields and then select the _Download_ button. Download from _divelogs.de_
starts immediately, displaying a progress bar in the dialogue box. At the
end of the download, the success status is indicated (see image *B*,
below). The _Apply_ button should then be selected, after which the imported
dives appear in the _Subsurface_ *Dive List* panel.

image::images/Divelogs1.jpg["FIGURE:Download from Divelogs.de", align="center"]

[[S_ImportingCSVData]]
==== Importer des données au format CSV

A comma-separated file (.csv) can be used to import dive information either
as dive profiles (as in the case of the APD Inspiration and Evolution closed
circuit rebreathers) or as dive metadata (in case the user keeps dive data
in a spreadsheet). The _CSV_ format is a universal simplified format that
allows for easy information exchange between different computers or software
packages. For an introduction to CSV-formatted files see xref:S_CSV_Intro[A
Diver's Introduction To CSV Files]. _Subsurface_ dive logs can also be
exported in _CSV_ format to other software that reads this format. See
xref:S_Appendix_D[APPENDIX D: Exporting a spreadsheet to CSV format] for
information that may be helpful for importing spreadsheet-based data into
_Subsurface_.

[[S_ImportingCSVDives]]
===== Importer les plongées au format CSV à partir des ordinateurs de plongées ou d'autres logiciels de carnet de plongée

One can view a _CSV_ file by using an ordinary text editor. It is normally
organised into a single line that provides the headers (or _field names_ or
_column headings_) of the data columns, followed by the data, one record per
line.

There are two types of _CSV_ dive logs that can be imported into
_Subsurface_:

1. _CSV dive details_: This dive log format contains similar information to
   that of a typical written dive log, e.g. dive date and time, dive depth,
   dive duration, names of buddy and dive master and perhaps some information
   about cylinder pressures before and after the dive, as well as a comment or
   two about the dive. All the data for a single dive go on a single line of
   text, following the order of the column headings.

2. _CSV dive profile_: This dive log format includes much more information
   about a single dive. For instance there may be information at 30-second
   intervals, indicating depth, water temperature at that depth, and cylinder
   pressure at that moment in time. Each line contains the information for a
   single instant in time during the dive, 30 seconds after that of the
   previous instant. Many lines are required to complete the depth profile
   information for a single dive. This is a common export format used by
   closed-circuit rebreather (CCR) dive equipment and many software packages
   that handle dive computer data and/or dive logs.

Before being able to import the _CSV_ data to _Subsurface_ *one needs to
know a few things about the data being imported*:

a. Which character separates the different columns within a single line of
   data? This field separator should be either a comma (,) a semicolon (;) or a
   TAB character.  This can be determined by opening the file with a text
   editor. If it is comma-delimited or semicolon-delimited, the comma or
   semicolon characters between the values are clearly visible. If these are
   not evident and the numbers are aligned in columns, the file is probably
   TAB-delimited (i.e. it uses a TAB as a field separator).

b. Which data columns need to be imported into _Subsurface_? Is it a _CSV dive
   details_ file or a _CSV dive profile_ file? Open the file using a text
   editor and note the titles of the columns to be imported and their column
   positions.

c. Is the numeric information (e.g. dive depth) in metric or in imperial unis?

Armed with this information, importing the data into _Subsurface_ is
straightforward. Select _Import -> Import Log Files_ from the main menu. In
the resulting file selection menu, select _CSV files_ (towards the bottom
right). This shows all .CSV files in the selected directory. Select the file
that needs to be imported. A configuration panel appears as depicted below:

image::images/csv_import1_f20.jpg["FIGURE: CSV download dialogue 1", align="center"]

Notice that, at the top left, there is a dropdown list containing
pre-configured settings for some of the more common dive computers and
software packages encountered by divers. If the _CSV_ file being imported
originated from any of these pre-configured items, then select it. Otherwise
use the _Manual Import_ option. The configuration panel also has dropdown
lists for the specification of the appropriate field separator (Tab, comma
or semicolon), the date format used in the _CSV_ file, the time units
(seconds, minutes or minutes:seconds), as well as the unit system (metric or
imperial). Selecting the appropriate options among these is critical for the
successful import of the data.

The last remaining task is to ensure that all the data columns have the
appropriate column headings. The top blue row of the data table contains the
column headings found in the _CSV_ data file. The blue row of balloons
immediately above these contains the names understood by _Subsurface_. These
balloons can be moved using a drag-and-drop action. For instance,
_Subsurface_ expects the column heading for Dive number (" # ") to be "Dive
# ". If the column heading that _Subsurface_ expects is not in the blue row,
then drag the appropriate balloon from the upper area and drop it in the
appropriate blue cell at the top of the table. To indicate the correct
column for "Dive #", drag the ballooned item labeled "Dive # " and drop it
in the blue cell immediately above the white cell containing " # ". This is
depicted in the image below.

image::images/csv_import2_f20.jpg["FIGURE: CSV download dialogue 2", align="center"]

Continue in this way to ensure that all the column headings in the blue row
of cells correspond to the headings listed in the top part of the
dialogue. Having completed this task, select the _OK_ button to the bottom
right of the dialogue.  The data from the _CSV_ file are imported and shown
in the *Dive List* panel.

[[S_CSV_Intro]]
****
*A Diver's Introduction to _CSV_ Files*
[icon="images/icons/important.png"]
[IMPORTANT]

_CSV_ is an abbreviation for a data file format: _Comma-Separated
Values_. It is a file format allowing someone to view or edit the
information using a text editor such as Notepad (Windows), gedit (Linux) or
TextWrangler (OS/X). The two main advantages of the _CSV_ format is that the
data are easily editable as text without any proprietary software and
ensuring all information is human-readable, not being obscured by any custom
or proprietary attributes that proprietary software insert into files.
Because of its simplicity the _CSV_ format is used as an interchange format
between many software packages, e.g. between spreadsheet, statistical,
graphics, database and diving software. Within _Subsurface_, _CSV_ files can
also be used to import information from other sources such as
spreadsheet-based dive logs and even from some dive computers.

_CSV_ files can be created or edited with a normal text editor. The most
important attribute of a _CSV_ file is the _field separator_, the character
used to separate fields within a single line. The field separator is
frequently a comma, a colon, a SPACE character or a TAB character. When
exporting data from spreadsheet software, the field separator needs to be
specified in order to create the _CSV_ file. _CSV_ files are normally
organised into a single line that provides the headers (or _field names_) of
the data columns, followed by the data, one record per line. Note that each
field name may comprise more than one word separated by spaces; for instance
_Dive site_, below. Here is an example of dive information for four dives
using a comma as a field separator:

	Dive site,Dive date,Time,Dive_duration, Dive_depth,Dive buddy
	Illovo Beach,2012-11-23,10:45,46:15,18.4,John Smith
	Key Largo,2012-11-24,09:12,34:15,20.4,Jason McDonald
	Wismar Baltic,2012-12-01,10:13,35:27,15.4,Dieter Albrecht
	Pulau Weh,2012-12-20,09:46,55:56,38.6,Karaeng Bontonompo

The above data are not easily read by a human. Here is the same information
in TAB-delimited format:

	Dive site	Dive date	Time	Dive_duration	Dive_depth	Dive buddy
	Illovo Beach	2012-11-23	10:45	46:15	18.4	John Smith
	Key Largo	2012-11-24	09:12	34:15	20.4	Jason McDonald
	Wismar Baltic	2012-12-01	10:13	35:27	15.4	Dieter Albrecht
	Pulau Weh	2012-12-20	09:46	55:56	38.6	Karaeng Bontonompo

It is clear why many people prefer the TAB-delimited format to the
comma-delimited format. The disadvantage is that one cannot see the TAB
characters. For instance, the space between _Dive_ and _date_ in the top
line may be a SPACE character or a TAB character (in this case it is a SPACE
character: the tabs are before and after _Dive date_). If the field names in
the first line are long, the alignment with data in the other lines cannot
be maintained. Here is a highly simplified and shortened TAB-delimited
example of a _CSV_ dive log from an APD closed-circuit rebreather (CCR) dive
computer:

	Dive Time (s)	Depth (m)	pO₂ - Setpoint (Bar) 	pO₂ - C1 Cell 1 (Bar)	Ambient temp. (Celsius)
	0       0.0     0.70    0.81    13.1
	0       1.2     0.70    0.71    13.1
	0       0.0     0.70    0.71    13.1
	0       1.2     0.70    0.71    13.2
	0       1.2     0.70    0.71    13.1
	10      1.6     0.70    0.72    12.7
	20      1.6     0.70    0.71    12.6
	30      1.7     0.70    0.71    12.6
	40      1.8     0.70    0.68    12.5

When a _CSV_ file is selected for import, _Subsurface_ displays the column
headers as well as some of the data in the first few lines of the _CSV_
file, making it much easier to work with _CSV_ files.  _CSV_ files can
therefore be used in many contexts for importing data into a _Subsurface_
dive log.  Knowledge of a few basic things about the content of the _CSV_
file allows a smooth import of the dives into _Subsurface_.

****


[icon="images/icons/important.png"]
[IMPORTANT]
The _CSV_ import has a couple of caveats. One should avoid some special
characters like ampersand (&), less than (<), greater than (>) and double
quotes (") as part of the numbers or text within a cell. The file should use
UTF-8 character set, if using non-ASCII characters. Also the size of the
_CSV_ file might cause problems. Importing 100 dives at a time (_CSV dive
details_) works, but larger files might exceed the limits of the parser
used. When encountering problems with _CSV_ imports, first try with a
smaller file to make sure everything works.


[[S_Companion]]
=== Importing GPS coordinates with the _Subsurface Companion App_ for mobile phones

Using the *Subsurface Companion App* on an _Android device_   or
xref:S_iphone[_iPhone_] with GPS, the coordinates
for the diving
location can be automatically passed to the _Subsurface_
dive log. The Companion App stores the dive locations on
a dedicated Internet file server. _Subsurface_, in turn, can collect
the localities from the file server.

To do this:

==== Create a Companion App account

- Register on the http://api.hohndel.org/login/[_Subsurface companion web
  page_].  A confirmation email with instructions and a personal *DIVERID*
  will be sent, a long number that gives access to the file server and
  Companion App capabilities.

- Download the app from
  https://play.google.com/store/apps/details?id=org.subsurface[Google Play
  Store] or from
  http://f-droid.org/repository/browse/?fdfilter=subsurface&fdid=org.subsurface[F-Droid].

==== Using the Subsurface companion app on an Android smartphone

On first use the app has three options:

* _Create a new account._ Equivalent to registering in _Subsurface_ companion
  page using an Internet browser. One can request a *DIVERID* using this
  option, but this is supplied via email and followed up by interaction with
  the http://api.hohndel.org/login/[_Subsurface companion web page_] in order
  to activate the account.

* _Retrieve an account._ If users forgot their *DIVERID* they will receive an
  email to recover the number.

* _Use an existing account._ Users are prompted for their *DIVERID*. The app
  saves this *DIVERID* and does not ask for it again unless one uses the
  _Disconnect_ menu option (see below).

[icon="images/icons/important.png"]
[IMPORTANT]
In the _Subsurface_ main program, the *DIVERID* should also be entered on
the Default Preferences panel, obtained by selecting _File -> Preferences ->
Defaults_ from the main menu in _Subsurface_ itself.  This facilitates
synchronisation between _Subsurface_ and the Companion App.

===== Creating new dive locations

Now one is ready to get a dive position and send it to the server. The
Android display will look like the left hand image (*A*) below, but without
any dives.

Touch the "+" icon on the top right to add a new dive site, a menu will be
showed with 3 options:

* Current: A prompt for a place name (or a request to activate the GPS if it
  is turned off) will be displayed, after which the current location is saved.

* Use Map: This option allows the user to fix a position by searching a world
  map. A world map is shown (see *B* below) on which one should indicate the
  desired position with a _long press_ on the touch sensitive screen (if the
  marked location is erroneous, simply indicate a new location)  and select
  the check symbol in the upper right. A dialog is shown allowing to enter the
  name of the dive location and the date-time of the dive (see *C* below). In
  order to import this dive location in _Subsurface_ it's advisable to set the
  time to agree with the time of that dive on the dive computer.

image::images/Companion_5.jpg["FIGURE: Companion App, add location using map", align="center"]


* Import local GPX file: The android device searches for .gpx files and
  located archives will be shown. The selected .gpx file is opened and the
  stored locations shown. Now one needs to select the appropriate locations,
  then select the tab in the upper right, after which the locations will be
  sent to the web service and added to the list on the Android device.

===== Dive lists of dive locations

The main screen shows a list of dive locations, each with a name, date and
time (see *A* below). Some locations may have an arrow-up icon over the
selection box to the left indicating that they require upload to the
server. One can select individual dive locations from the list. A selected
location has a check mark in the selection box on the left. Group operations
(such as _Delete_ or _Send_)  are performed on several locations that are
selected.

Dive locations in this list can be viewed in two ways: a list of locations
or a map indicating the dive locations. The display mode (List or Map) is
changed by selecting _Dives_ at the top left of the screen (see *A* below)
and then selecting the display mode. The display mode can be changed either
from the list of locations or from the map (see *B* below). If one selects a
location (on the list or on the map), an editing panel opens (see *C* below)
where the dive description or other details may be changed.

image::images/Companion_4.jpg["FIGURE: Companion App, add location using map", align="center"]


When one selects a dive (*not* selecting the check box), the name given to
it, date/time and GPS coordinates will be shown, with two options at the top
of the screen:

- Edit (pencil): Change the text name or other characteristics of the dive
  location.

- Maps: Display a map showing the dive location.

After editing and saving a dive location (see *C* above), one needs to
upload it to the web service, as explained below.

===== Uploading dive locations

There are several ways to send locations to the server.  The easiest is by
simply selecting the locations (See *A* below) and then touching the right
arrow at the top right of the screen.

[icon="images/icons/important.png"]
[IMPORTANT]
Users must be careful, as the trash icon on the right means exactly what it
should; it deletes the selected dive location(s).

image::images/Companion_1.jpg["FIGURE: Screen shots (A-B) of companion app", align="center"]


After a dive trip using the Companion App, all dive locations are ready to
be downloaded to a _Subsurface_ dive log (see below).


===== Settings on the Companion app

Selecting the _Settings_ menu option results in the right hand image above
(*B*).

===== Server and account

- _Web-service URL._ This is predefined (http://api.hohndel.org/)

- _User ID._ The DIVERID obtained by registering as described above. The
  easiest way to obtain it is simply to copy and paste from the confirmation
  email but, of course, users can also type this information.

===== Synchronisation

- _Synchronize on startup._ If selected, dive locations in the Android device
  and those on the web service synchronise each time the app is started.

- _Upload new dives._ If selected, each time the user adds a dive location it
  is automatically sent to the server.

===== Background service
Instead of entering a unique dive location, users can leave the service
running in the background of their Android device, allowing the continuous
collection of GPS locations.


The settings below define the behaviour of the service:

- _Min duration._ In minutes. The app will try to get a location every X
  minutes until stopped by the user.

- _Min distance._ In meters. Minimum distance between two locations.

- _Name template._ The name the app will use when saving the locations.

[icon="images/icons/info.jpg"]
[TIP]
_How does the background service work?_ Assuming the user sets 5 minutes and
50 meters in the settings above, the app will start by recording a location
at the current location, followed by another one at every 5 minutes *or*
every time one moves 50m from previous location.  If subsequent locations
are within a radius of 50 meters from the previous one, a new location is
not saved. If the user is not moving, only one location is saved, but if the
user is moving, a trace of the route is obtained by saving a location every
50 meters.

===== Other

_Mailing List._ The mail box for _Subsurface_. Users can send an email to
the Subsurface mailing list.

- _Subsurface website._ A link to the URL of Subsurface web

- _Version._ Displays the current version of the Companion App.

===== Search

Search the saved dive locations by name or by date and time.

===== Start service

Initiates the _background service_ following the previously defined
settings.

===== Disconnect

This is a badly named option that disconnects the app from the server by
resetting the user ID in the app, showing the first screen where an account
can be created, retrieve the ID for an existing account or use the users own
ID. The disconnect option is useful if a user's Android device was used to
download the dive locations of another registered diver.

===== Send all locations

This option sends all locations stored in the Android device to the server.

[[S_iphone]]
==== Using the Subsurface companion app on an _iPhone_ to record dive locations

The iPhone interface is quite simple. One needs to type the user ID
(obtained during registration) into the space reserved for it, then select
"Dive in" (see left part of the image below) and start collecting dive
location information.

image::images/iphone.jpg["FIGURE: Using iPhone companion application", align="center", width=640]

Dives can be added automatically or manually. In manual mode, a dive
location or waypoint is added to the GPS input stream. In automatic mode, a
continuous path of GPS locations is created from which, much later, after
import, subsurface can select the appropriate GPS locations based on the
times of dives. The default mode for the _iphone_ is automatic. When one
adds a dive, the location service is started automatically and a red bar
appears at the bottom of the screen. After the dive one can click on the red
bar to end the location service. While the location service is running one
can only add dives using the manual mechanism.

One can edit the site name afterwards by selecting the dive from the dive
list and clicking on the site name. There are no other editable fields. The
dive list is automatically uploaded from the iphone to the webservice and
there is not an option to trigger upload manually.


==== Downloading dive locations to the _Subsurface_ divelog

Download dive(s) from a dive computer or enter them manually into
_Subsurface_ before obtaining the GPS coordinates from the server. The
download dialog can be reached via _Ctrl+G_ or from the _Subsurface_ Main
Menu _Import -> Import GPS data from Subsurface Service_, resulting in the
image on the left (*A*), below. On first use the DIVERID text box is
blank. Provide a DIVERID, then select the _Download_ button to initiate the
download process, after which the screen on the right (*B*) below appears:

image::images/DownloadGPS.jpg["FIGURE: Downloading Companion app GPS data", align="center"]

Note that the _Apply_ button is now active. By clicking on it, users can
update the locations of the newly entered or uploaded dives in _Subsurface_
which applies the coordinates and names entered on the app for all the new
dives that match the date-times of the uploaded GPS localities. If one has
entered the name of the dive location in _Subsurface_ before downloading the
GPS coordinates, this name will take precedence over downloaded one.

Since _Subsurface_ matches GPS locations from the Android device and dive
information from the dive computer based on date-time data, automatic
assignment of GPS data to dives is dependent on agreement of the date-time
information between these two devices. Although _Subsurface_ has a wide
range tolerance, it may be unable to identify the appropriate dive if there
is a large difference between the time in the dive computer and that of the
Android device, resulting in no updates.

Similar date-times may not always be possible and there may be many reasons
for this (e.g. time zones), or _Subsurface_ may be unable to decide which is
the correct position for a dive (e.g. on repetitive dives while running
_background service_ there may be several locations that would be included
in the time range that fit not only the first dive, but one or more
subsequent dives as well).  A workaround for this situation to manually edit
the date-time of a dive in the _Subsurface_ Dive List *before* downloading
the GPS data and then to change the date-time back again *after* downloading
GPS data.

[icon="images/icons/info.jpg"]
[NOTE]
TIPS:

- _Background service_, being a very powerful tool, may fill the location list
  with many unnecessary locations not corresponding to the exact dive point
  but reflecting the boat's route.  Currently these locations are difficult to
  delete from the server. In some situations it is therefore prudent to clean
  up the list on the Android device before sending the dive points to the web
  server by simply deleting the inappropriate locations. This might be
  necessary, for instance, if one wants to keep the location list clear to see
  dives in the web service map display (see above).

- It may also make sense to give informative names to the locations sent to
  the web server, or at least to use an informative name in the _Name
  Template_ setting while running the _background service_, especially on a
  dive trip with many dives and dive locations.

[[S_LoadImage]]
=== Adding photographs to dives

Many (if not most) divers take a camera with them and take photographs
during a dive. One would like to associate each photograph with a specific
dive. _Subsurface_ allows one to load photos into a dive. Photos are
superimposed on the dive profile, from where they can be viewed.

==== Loading photos and getting synchronisation between dive computer and camera

Left-lick on a dive or on a group of dives on the dive list. Then
right-click on this dive or group of dives and choose the option _Load
Images_:

image::images/LoadImage1_f20.jpg["FIGURE: Load images option", align="center"]

The system file browser appears. Select the folder and photographs that need
to be loaded into _Subsurface_ and click the _Open_ button.

image::images/LoadImage2_f20.jpg["FIGURE: Load images option", align="center"]

This brings up the time synchronisation dialog, shown below. The critical
problem is that the time synchronisation is not perfect between the dive
computer used during a dive, and the camera used during that same
dive. These two devices often differ by several minutes. If _Subsurface_ can
achieve synchronisation, then the exact times of photographs can be used to
position photographs on the dive profile.

_Subsurface_ achieves this synchronisation in three ways:

- *Pro-actively*: Before the dive, ensure synchronisation of the dive computer time settings with
  the time settings of the camera by changing the date-time settings on one or both of these devices.
- *Manually*: If the user wrote down the exact camera time at the start of a dive, the
  difference in time between the two devices can be determined. Actually, as long as the device
  settings for time has not been changed in either device, one could write down the times of
  both devices after the dive or even at the end of the day. One can then manually set the time
  difference in the _Time shift_ dialog. Towards the top of the dialog is a time setting tool
  immediately under the heading _Shift times of image(s) by_, evident in figure *A* below.
  If the camera time is 7 minutes later than that of the dive computer, set the time setting
  tool to a value of 00:07.  Select either the _earlier_ or _later_ radio button.
  In the above example, the _earlier_ option is appropriate, since the photos need to be shifted
  7 minutes earlier (camera is 7 minutes ahead of dive computer). Ignore any "AM" or "PM" suffix
  in that tool. Click the _OK_ button and synchronisation is achieved.

image::images/LoadImage3b_f20.jpg["FIGURE: Synchronisation dialog", align="center"]


- *By photograph*: There is a very slick way of achieving synchronisation. If one takes a
  photograph of the face of the dive computer showing the time, then _Subsurface_ can obtain
  the exact time the photograph was taken, using the metadata that the camera stores within
  each photo. In order to do this, use the bottom half of the _Time shift_ dialog. If one uses
  the bottom part, the top part of the dialog is ignored. Click on
  the horizontal bar entitled "_Select image of divecomputer showing time_. This brings up
  a file browser with which one can select the photograph of the dive computer time. Select the
  photograph using the file browser and click on _OK_. This photograph of the dive computer
  appears in the bottom panel of the _Shift times_ dialog. Now _Subsurface_ knows exactly
  when the photograph has been taken. Now set the date-time dialog to the left of the photo
  so that this tool reflects the date and time of the dive computer in the photo. When the
  date-time tool has been set, _Subsurface_ knows exactly what the time difference between
  camera and dive computer is, and synchronisation is achieved.
  Image *B* above shows a photograph of the face of the dive computer and with the date-time tool set to the
  date-time.

If the timestamp of a photograph is more than 30 minutes before or after the
dive, it is not placed on the dive profile.

==== Viewing the photos

After the images have been loaded, they appear in two places:

 - the _Photos_ tab of the *Notes* panel.
 - as tiny icons (stubs) on the dive profile at the appropriate positions
   reflecting the time each photograph was taken.  In order to view the photos
   on the dive profile, activate the _show-photos_ button in the tool bar to
   the left of the dive profile:

image::images/icons/ShowPhotos_f20.png["FIGURE:Show photos toolbar button", align="left"]

This results in a profile display as in the image below:

image::images/LoadImage4_f20.jpg["FIGURE: Photos on dive profile", align="center"]

If one hovers with the mouse over any of the photo icons, then a thumbnail
photo is shown of the appropriate photo. See the image below:

image::images/LoadImage5_f20.jpg["FIGURE:Thumbnail photo on dive profile", align="center"]

Clicking on the thumbnail brings up a full size photo overlaid on the
_Subsurface_ window. This allows good viewing of the photographs that have
been added (see the image below). Note that the thumbnail has a small
dustbin icon in the bottom right hand corner (see image above). If one
selects the dustbin, the image is removed from the dive. Therefore some care
is required when clicking on a thumbnail. Images can also be deleted using
the _Photos_ tab (see text below).

image::images/LoadImage6_f20.jpg["FIGURE: Full-screen photo on dive profile", align="center"]

==== The _Photos_ tab

Photographs associated with a dive are shown as thumbnails in the _Photos_
tab of the _Notes_ panel. Photos taken in rapid succession during a dive
(therefore sometimes with large overlap on the dive profile) can easily be
accessed in the _Photos_ tab. This tab serves as a tool for individually
accessing the photos of a dive, while the stubs on the dive profile give an
indication of when during a dive a photo was taken. By single-clicking on a
thumbnail in the _Photos_ panel, a photo is selected. By double-clicking a
thumbnail, the full-sized image is shown, overlaying the _Subsurface_
window. A photo can be deleted from the _Photos_ panel by selecting it
(single-click) and then by pressing the _Del_ key on the keyboard. This
removes the photo both from the _Photos_ tab as well as the dive profile.

==== Photos on an external hard disk

Most underwater photographers store their photos on an external drive. If
such a drive can be mapped by the operating system (almost always the case)
the photos can be directly accessed by _Subsurface_. This facilitates the
interaction between _Subsurface_ and an external repository of photos. When
associating a dive profile with photos from an external drive, the normal
procedure of selection and synchronisation (see text above) is used.
However, after the external drive has been disconnected, _Subsurface_ cannot
access these photos any more.  If the display of photos is activated (using
the toolbox to the left of the _Dive Profile_), the program only shows a
small white dot where each photo should be on the dive profile.  In addition
the _Photos_ tab only shows the file names of the photos. This is normal
behaviour.  If, later, the external drive with the photos is connected
again, the photos can be seen in the normal way.

[[S_FindMovedImages]]
==== Moving photographs among directories, hard disks or computers

After a photograph has been loaded into _Subsurface_ and associated with a specific dive, the directory
 where the photo lies is stored, allowing _Subsurface_ to find the photograph when the dive is
 opened again. If the photo or the whole photo collection is moved to another drive or to a different
 machine, it is unlikely that the directory structure will remain identical to that of the original uploaded
 photo. When this happens, _Subsurface_ looks for the photos at their original location before they were moved,
 cannot find them and therefore cannot display them. Because, after moving photos, large numbers of photos
 may need to be deleted and re-imported from the new location, _Subsurface_ has a mechanism that eases the
 process of updating the directory information for each photo: automatic updates using fingerprints.

When a photo is loaded into _Subsurface_, a fingerprint for the image is calculated and stored with the
 other reference information for that photo. After moving a photo collection (that has already been loaded
 into _Subsurface_) to a different directory, disk or computer, _Subsurface_ can  perform the
 following steps:

- look through a particular directory (and all its subdirectories recursively)
  where photos have been moved
 to,

- calculate fingerprints for all photos in this directory, and

- if there is a match between a calculated fingerprint and the one originally
  calculated when a photo was
 loaded into _Subsurface_ (even if the original file name has changed), to
 automatically update the directory information so that _Subsurface_ can find
 the photo in the new moved directory.

This is achieved by selecting from the Main Menu: _File ->      Find moved images_. This brings up a window within
 which the NEW directory of the photos needs to be specified. Select the appropriate directory and click
 the _Scan_ button towards the bottom right of the panel. The process may require several minutes to
 complete, after which _subsurface_ will show the appropriate photographs when a particular dive is opened.


[[Image_fingerprint_upgrade]]
****
*Upgrading existing photo collections without fingerprints*
[icon="images/icons/important.png"]
[IMPORTANT]

Software for the automated finger print calculation of existing photo
collections is under developement. Currently single dives must be upgraded
one at a time. Select the toolbar button on the *Dive profile* panel that
enables the display of images. The thumbnails of images are shown on the
dive profile. Then open the dive and change anything in the *Notes* panel
that brings up the blue edit bar at the top of the notes panel to save the
edits. For instance, add a space character at the end of the _Notes_ text
box and immediately delete that space character. Select the optio _Apply
changes_ in the blue edit bar to save the dive information.  Fingerprints
are calculated while saving this specific dive.

****


=== Logging special types of dives

[[S_MulticylinderDives]]
==== Multicylinder dives

_Subsurface_ easily handles dives involving more than one
cylinder. Multicylinder diving usually happens (a) if a diver does not have
enough gas for the complete dive in a single cylinder; (b) if the diver
needs more than one gas mixture because of the depth or the decompression
needs of the dive. For this reason multicylinder dives are often used by
technical divers who dive deep or long. As far as _Subsurface_ is concerned,
there are only two types of information that need to be provided:

- *Describe the cylinders used during the dive* This is performed in the *Equipment tab* of
  the *Info* panel, as xref:cylinder_definitions[described above]. Enter the cylinders one by one,
  specifying the characteristics of the cylinder and the gas composition within each cylinder.

- *Record the times at which switches from one cylinder to another was done:* This is information
  provided by some dive computers (provided the diver indicated these changes to the dive computer
  by pressing specific buttons). If the dive computer does not provide the information, the diver has to
  record these changes using a different method, e.g. writing it on a slate.

- *Record the cylinder changes on the dive profile*: If the latter option
  was followed, the diver needs to indicate the gas change event by right-clicking at the appropriate point
  in time on the *Dive Profile* panel and indicating the cylinder to which the change was made. After
  right-clicking, follow the context menu to "Add gas change" and select the appropriate cylinder from
  those defined during the first step, above (see image below). If the
  *tank bar* button in the toolbar has been activated, the cylinder switches are also indicated in the
  tank bar.

Having performed these tasks, _Subsurface_ indicates the appropriate use of
cylinders in the dive profile.  Below is a multi-cylinder dive, starting off
with EAN28, then changing cylinders to EAN50 after 26 minutes to perform
decompression.

image::images/multicylinder_dive.jpg["FIGURE: Multicylinder profile", align="center"]

==== Sidemount dives

Sidemount diving is just another form of multicylinder diving, often with
both or all cylinders having the same gas mixture. Although it is a popular
configuration for cave divers, sidemount diving can be performed by
recreational divers who have completed the appropriate training. Sidemount
dive logging involves, exactly as with multicylinder dives, above, three
steps:

- *During the dive, record cylinder switch events*. Since sidemount diving normally involves two
  cylinders with air or with the same gas mixture, _Subsurface_ distinguishes among these different
  cylinders. In contrast, many dive computers that allow gas switching only distinguish among different
  _gases_ used, not among different _cylinders_ used. This means that when sidemount dives are downloaded
  from these dive computers, the events of switching between cylinders with the same gas are not downloaded. This may mean
  that one may have to keep a written log of cylinder switch times using a slate, or (if the dive computer
  has this facility) marking each cylinder switch with a bookmark that can be retrieved later. Returning
  from a dive with the times of cylinder changes is the only tricky part of logging sidemount dives.
- *Within _Subsurface_ describe the cylinders used during the dive*. The diver needs to provide the
  specifications of the different cylinders, using the *Equipment* tab of the *Info Panel* (see
  image below where two 12 litre cylinder were used).
- *Indicate cylinder change events on the _Subsurface_ dive profile*. Once the dive log has been imported
  from a dive computer into _Subsurface_, the cylinder switch events need to be indicated on the dive profile.
  Cylinder changes are recorded by right-clicking at the appropriate point on the dive profile and then
  selecting _Add gas change_. A list of the appropriate cylinders is shown with the
  currently used cylinder greyed out. In the image below Tank 1 is greyed out, leaving only Tank 2
  to be selected. Select the appropriate cylinder. The cylinder change is then indicated on the dive
  profile with a cylinder symbol. If the *Tank Bar* is activated using the toolbar to the left of the
  profile, then the cylinder change is also indicated on the Tank Bar (see image below). After all
  the cylinder change events have been recorded on the dive profile, the correct cylinder pressures
  for both cylinders are shown on the dive profile, as in the image below.

image::images/sidemount1.jpg["FIGURE: Sidemount profile", align="center"]

This section gives an example of the versatility of _Subsurface_ as a dive
logging tool.


[[S_sSCR_dives]]
==== Semi-closed circuit rebreather (SCR) dives

[icon="images/halcyon_RB80.jpg"]
[NOTE]
Passive semi-closed rebreathers (pSCR) comprise a technical advance in
diving equipment that recirculates the breathing gas that a diver breathes,
while removing carbon dioxide from the exhaled gas. While a small amount
(typically a tenth) of the exhaled breathing gas is released into the water,
a small amount of fresh gas is released from the back gas cylinder
(typically containing nitrox).  A diver, using a single cylinder of
breathing gas can therefore dive for much longer periods than using a
recreational open-circuit configuration. With pSCR equipment, a very small
amount of breathing gas is released every time the breather inhales. With
active SCR (aSCR) equipment, in contrast, a small amount of breathing gas is
released continuously from the back cylinder.

To log pSCR dives, no special procedures are required, just the normal steps
outlined above:

- Select pSCR in the _Dive Mode_ dropdown list on the *Info* panel.

- pSCR diving often involves gas changes, requiring an additional cylinder.
  Define all the appropriate cylinders as described above and indicate the
  cylinder/gas changes as described above in the section on
  xref:S_MulticylinderDives[multicylinder dives].

If a pSCR _Dive Mode_ has been selected, the dive ceiling for pSCR dives is
adjusted for the oxygen drop across the mouthpiece which often requires
longer decompression periods. Below is a dive profile of a pSCR dive using
EAN36 on the back cylinder and oxygen for decompression. Note that this dive
lasted over two hours.

image::images/pSCR_profile.jpg["FIGURE: pSCR profile", align="center"]



[[S_CCR_dives]]
==== Closed circuit rebreather (CCR) dives

[icon="images/APD.jpg"]
[NOTE]
Closed system rebreathers use advanced technology to recirculate gas that
has been breathed while doing two things to maintain a breathable oxygen
concentration:
a) remove carbon dioxide from the gas that has been exhaled
regulate the oxygen concentration to remain within safe diving limits.  The
CCR interface of _Subsurface_ is currently experimental and under active
development. Subsurface currently supports Poseidon MkVI and APD
Discovery/Evolution dive computers. In contrast to a conventional
recreational dive computer, a CCR system computer does not allow the
download of a log containing multiple dives. Rather, each dive is stored
independently. This means that _Subsurface_ cannot download a dive log
directly from a CCR dive computer, but that it imports CCR dive logs in the
same way that it imports dive log data from other digital databases: one
dive at a time.

===== Import a CCR dive

See the section dealing with xref:S_ImportingAlienDiveLogs[Importing dive
information from other digital sources]. From the main menu of _Subsurface_,
select _Import -> Import log files_ to bring up the
xref:Unified_import[universal import dialogue]. As explained in that
section, the bottom right hand of the import dialogue contains a dropdown
list (labled _Filter:_) of appropriate devices that currently
includes(Poseidon) MkVI or APD log viewer files (import for other CCR
equipment is under active development). Having selected the appropriate CCR
format and the directory where the original dive logs have been stored from
the CCR dive computer, one can select a particular dive log file (in the
case of the MkVI it is a file with a .txt extension). After selecting the
appropriate dive log, activate the _Open_ button at the bottom right hand of
the universal import dialogue.  The selected dive is imported to the
_Subsurface_ dive list.

===== Displayed information for a CCR dive

_Partial pressures of gases_: The graph of oxygen partial pressure shows the
information from the oxygen sensors of the CCR equipment. In contrast to
recreational equipment (where pO~2~ values are calculated based on gas
composition and dive depth), CCR equipment provide actual measurements of
pO~2~, derived from oxygen sensors.  In this case the graph for oxygen
partial pressure should be fairly flat, reflecting the setpoint settings
during the dive. The mean pO~2~ is NOT the mean oxygen partial pressure as
given by the CCR equipment, but a value calculated by _Subsurface_ as
follows:

- For TWO O~2~ sensors the mean value of the two sensors are given.

- For THREE-sensor systems (e.g. APD), the mean value is also used. However
  differences of more than 0,1 bar in the simultaneous readings of different
  sensors are treated as spurious. If one of the three sensors provides
  spurious data, it is ignored.

- If no sensor data are available, the pO~2~ value is assumed to be equal to
  the setpoint.

The mean pO~2~ of the sensors is indicated with a green line,

The oxygen setpoint values as well as the readings from the individual
oxygen sensors can be shown. The display of additional CCR information is
turned on by checking the appropriate checkboxes in the _Preferences_ panel
(accessible by selecting xref:S_CCR_options[_File -> Preferences ->
Graph_]). This part of the _Preferences_ panel is shown in the image below,
representing two checkboxes that modify the display of pO~2~ when the
appropriate toolbar button on the Dive Profile has been activated.

image::images/CCR_preferences_f20.jpg["FIGURE: CCR preferences panel", align="center"]

Checking any of these check boxes allows the display of additional
oxygen-related information whenever the pO~2~ toolbar button on the
_Profile_ panel is activated.  The first checkbox allows the display of
setpoint information. This is a red line superimposed on the green oxygen
partial pressure graph and allows a comparison of the mean measured oxygen
partial pressure and the setpoint values, as shown below.

image::images/CCR_setpoint_f20.jpg["FIGURE: CCR setpoint and po2 graph", align="center"]

The second checkbox allows the display of the data from each individual
oxygen sensor of the CCR equipment. The data for each sensor is colour-coded
as follows:

- Sensor 1: grey
- Sensor 2: blue
- Sensor 3: brown

The mean oxygen pO~2~ is indicated by the green line. This allows the direct
comparison of data from each of the oxygen sensors, useful for detecting
abnormally low or erratic readings from a particular sensor.

image::images/CCR_sensor_data_f20.jpg["FIGURE: CCR sensor data graph", align="center"]

The setpoint data can be overlaid on the oxygen sensor data by activating
both of the above check boxes. Partial pressures for nitrogen (and helium,
if applicable) are shown in the usual way as for open circuit dives.

_Events_: Several events are logged, e.g. switching the mouthpiece to open
circuit.  These events are indicated by yellow triangles and, if one hovers
over a triangle, a description of that event is given as the bottom line in
the xref:S_InfoBox[Information Box].

_Cylinder pressures_: Some CCR dive computers like the Poseidon MkVI record
the pressures of the oxygen and diluent cylinders. The pressures of these
two cylinders are shown as green lines overlapping the depth profile. In
addition, start and end pressures for both oxygen and diluent cylinders are
shown in the _Equipment Tab_.  Below is a dive profile for a CCR dive,
including an overlay of setpoint and oxygen sensor data, as well as the
cylinder pressure data. In this case there is good agreement from the
readings of the two oxygen sensors.

image::images/CCR_dive_profile_f22.jpg["FIGURE: CCR dive profile", align="center"]

_Equipment-specific information_: Equipment-specific information gathered by
_Subsurface_ is shown in the xref:S_ExtraDataTab[Extra data tab]. This may
include setup information or metadata about the dive.

The deco ceiling calculated by Subsurface is not very accurate because the
precise pressure of nitrogen in the loop can usually not be determined from
the dive log imported from the CCR equipment. Many CCR dive computers,
however, report an internally-calculated deco ceiling that is reported in
the dive log, reflecting a more accurate assessment. The display of this
ceiling is activated by clicking the appropriate button to the left of the
dive profile:

image::images/icons/cceiling.jpg["DC ceiling icon"]

The default colour of the computer-generated deco ceiling is white. However,
this can be set to red by checking the appropriate check box after selecting
_File -> Preferences -> Graph_.  Below is a dive profile indicating the dive
computer-generated deco ceiling:

image::images/CCR_dive_ceilingF22.jpg["FIGURE: CCR computer-generated deco ceiling", align="center"]

More equipment-specific information for downloading CCR dive logs for
Poseidon MkVI and APD equipment can be found in
xref:_appendix_b_dive_computer_specific_information_for_importing_dive_information[Appendix
B].

== Obtaining more information about dives entered into the logbook

=== The *Info* tab (for individual dives)

The Info tab gives some summary information about a particular dive that has
been selected in the *Dive List*. Useful information here includes the
surface interval before the dive, the maximum and mean depths of the dive,
the gas volume consumed, the surface air consumption (SAC) and the number of
oxygen toxicity units (OTU) incurred.

[icon="images/icons/info.jpg"]
[NOTE]
Gas consumption and SAC calculations: _Subsurface_ calculates SAC and Gas
consumption taking in account gas incompressibility, particularly at tank
pressures above 200 bar, making them more accurate.  Users should refer to
xref:SAC_CALCULATION[Appendix D] for more information.

[[S_ExtraDataTab]]
=== The *Extra Data* tab (usually for individual dives)

When using a dive computer, it often reports several data items that cannot
easily be presented in a standardised way because the nature of the
information differs from one dive computer to another. These data often
comprise setup information, metadata about a dive, battery levels, no fly
times, or gradient factors used during the dive. When possible, this
information is presented in the *Extra Data* tab. Below is an image showing
extra data for a dive using a Poseidon rebreather.

image::images/ExtraDataTab_f20.jpg["FIGURE: Extra Data tab", align="center"]

=== The *Stats* tab (for groups of dives)

The Stats tab gives summary statistics for more than one dive, assuming that
more than one dive has been selected in the *Dive List* using the standard
Ctrl-click or Shift-click of the mouse. If only one dive has been selected,
figures pertaining to only that dive are given. This tab shows the number of
dives selected, the total amount of dive time in these dives, as well as the
minimum, maximum and mean for the dive duration, water temperature and
surface air consumption (SAC). It also shows the depth of the shallowest and
deepest dives of those selected.

[[S_DiveProfile]]
=== The *Dive Profile*

image::images/Profile2.jpg["Typical dive profile", align="center"]

Of all the panels in _Subsurface_, the Dive Profile contains the most
detailed information about each dive. The Dive Profile has a *button bar* on
the left hand side that allows control over several display options. The
functions of these buttons are described below. The main item in the Dive
Profile is the graph of dive depth as a function of time. In addition to the
obvious information of the depth it also shows the ascent and descent rates
compared to the recommended speed of going up or down in the water
column. This information is given using different colours:
|====================
|*Couleur*|*Vitesse de descente (m/min)*|*Vitesse de remontée (m/min)*
|Rouge|> 30|> 18
|Orange|18 - 30|9 - 18
|Jaune|9 - 18|4 - 9
|Vert clair|1.5 - 9|1.5 - 4
|Vert foncé|< 1.5|< 1.5
|=====================

The profile also includes depth readings for the peaks and troughs in the
graph.  Thus, users should see the depth of the deepest point and other
peaks. Mean depth is plotted as a grey line, indicating mean dive depth up
to a particular moment during the dive.

[icon="images/icons/scale.jpg"]
[NOTE]
In some cases the dive profile does not fill the whole area of the *Dive
Profile* panel. Clicking the *Scale* button in the toolbar on the left of
the dive profile frequently increases the size of the dive profile to fill
the area of the panel efficiently.

*Water temperature* is displayed with its own blue line with temperature values
placed adjacent to significant changes.

The dive profile can include graphs of the *partial pressures* of O~2~,
N~2~, and He during the dive (see figure above) as well as a calculated and
dive computer reported deco ceilings (only visible for deep, long, or
repetitive dives).  Partial pressures of oxygen are indicated in green,
those of nitrogen in black, and those of helium in dark red. These partial
pressure graphs are shown below the profile data.

[icon="images/icons/O2.jpg"]
[NOTE]
Clicking this button allows display of the partial pressure of *oxygen*
during the dive. This is depicted below the dive depth and water temperature
graphs.

[icon="images/icons/N2.jpg"]
[NOTE]
Clicking this button allows display of the partial pressure of *nitrogen*
during the dive.

[icon="images/icons/He.jpg"]
[NOTE]
Clicking this button allows display of the partial pressure of *helium*
during the dive.  This is only of importance to divers using Trimix,
Helitrox or similar breathing gasses.

The *air consumption* graph displays the tank pressure and its change during
the dive. The air consumption takes depth into account so that even when
manually entering the start and end pressures the graph is not a straight
line.  Similarly to the depth graph the slope of the tank pressure gives the
user information about the momentary SAC rate (Surface Air Consumption) when
using an air integrated dive computer.  Here the colour coding is not
relative to some absolute values but relative to the average normalised air
consumption during the dive. So areas that are red or orange indicate times
of increased normalized air consumption while dark green reflects times when
the diver was using less gas than average.

[icon="images/icons/Heartbutton.png"]
[NOTE]
Clicking on the heart rate button will allow the display of heart rate
information during the dive if the dive computer was attached to a heart
rate sensor.

It is possible to *zoom* into the profile graph. This is done either by using
the scroll wheel / scroll gesture of your mouse or trackpad. By default
_Subsurface_ always shows a profile area large enough for at least 30 minutes
and 30m
 (100ft) – this way short or shallow dives are intuitively recognizable;
something
that free divers clearly won’t care about.

image::images/MeasuringBar.png["FIGURE: Measuring Bar", align="center"]

[icon="images/icons/ruler.jpg"]
[NOTE]
Measurements of *depth or time differences* can be achieved by using the
*ruler button* on the left of the dive profile panel.  The measurement is
done by dragging the red dots to the two points on the dive profile that the
user wishes to measure. Information is then given in the horizontal white
area underneath the two red dots.

[icon="images/icons/ShowPhotos.png"]
[NOTE]
Photographs that have been added to a dive can be shown on the profile by
selecting the *Show-photo* button. The position of a photo on the profile
indicates the exact time when this photo was taken. If this button is not
active, the photos are hidden.


The profile can also include the dive computer reported *ceiling* (more
precisely, the deepest deco stop that the dive computer calculated for each
particular moment in time) as a red overlay on the dive profile. Ascent
ceilings arise when a direct ascent to the surface increases the risk of a
diver suffering from decompression sickness (DCS) and it is necessary to
either ascend slower or to perform decompression stop(s) before ascending to
the surface. Not all dive computers record this information and make it
available for download; for example all of the Suunto dive computers fail to
make this very useful data available to divelog software. _Subsurface_ also
calculates ceilings independently, shown as a green overlay on the dive
profile.  Because of the differences in algorithms used and amount of data
available (and other factors taken into consideration at the time of the
calculation) it is unlikely that ceilings from dive computers and from
_Subsurface_ are the same, even if the same algorithm and _gradient factors_
(see below) are used.  It is also quite common that _Subsurface_ calculates
a ceiling for non-decompression dives when the dive computer stayed in
non-deco mode during the whole dive (represented by the [green]#dark green#
section in the profile at the beginning of this section). This is caused by
the fact that _Subsurface’s_ calculations describe the deco obligation at
each moment during a dive, while dive computers usually take the upcoming
ascent into account. During the ascent some excess nitrogen (and possibly
helium) are already breathed off so even though the diver technically
encountered a ceiling at depth, the dive still does not require an explicit
deco stop. This feature allows dive computers to offer longer non-stop
bottom times.

[icon="images/icons/cceiling.jpg"]
[NOTE]
If the dive computer itself calculates a ceiling and makes it available to
_Subsurface_ during upload of dives, this can be shown as a red area by
checking *Dive computer reported ceiling* button on the Profile Panel.

[icon="images/icons/ceiling1.jpg"]
[NOTE]
If the *Calculated ceiling* button on the Profile Panel is clicked, then a
ceiling, calculated by _Subsurface_, is shown in green if it exists for a
particular dive (*A* in figure below). This setting can be modified in two
ways:

[icon="images/icons/ceiling2.jpg"]
[NOTE]
If, in addition, the *show all tissues* button on the Profile Panel is
clicked, the ceiling is shown for the tissue compartments following the
Bühlmann model (*B* in figure below).

[icon="images/icons/ceiling3.jpg"]
[NOTE]
If, in addition, the *3m increments* button on the Profile Panel is clicked,
then the ceiling is indicated in 3 m increments (*C* in figure below).

image::images/Ceilings2.jpg["Figure: Ceiling with 3m resolution", align="center"]

[icon="images/icons/ShowCylindersButton.jpg"]
[NOTE]
By selecting this icon, the different cylinders used during a dive can be
represented as a coloured bar at the bottom of the *Dive Profile*. In
general oxygen is represented by a green bar, nitrogen with a yellow bar and
helium with a red bar. The image below shows a dive which first uses a
trimix cylinder (red and green), followed by a switch to a nitrox cylinder
(yellow and green) after 23 minutes. Cylinders with air are shown as a light
blue bar.

image::images/ShowCylinders_f20.jpg["Figure: Cylinder use graph", align="center"]


[icon="images/tissues.jpg"]

[NOTE]
Display inert gas tissue pressures relative to ambient inert gas pressure
(horizontal grey line).  Tissue pressures are calculated using the Bühlmann
ZH-L16 algorithm and are displayed as lines ranging from green (faster
tissues) to blue (slower tissues).  The black line, graphed above the
ambient pressure, is the maximum allowable tissue supersaturation (pressure
limit) derived from the gradient factors specified in the *Preferences*. For
divers involved in planned decompression diving, efficient rates of
offgasing are obtained with tissue pressures between the ambient inert gas
pressure (grey line) and the pressure limit (black line). This display is a
representation of the tissue pressures during the whole dive. In contast,
the xref:S_gas_pressure_graph[Gas Pressure Graph] in the *Information Box*
on the *Dive Profile* is an instantaneous reflection of tissue pressures at
the moment in time reflected by the position of the cursor on the dive
profile.

image::images/tissuesGraph.jpg["Figure: Inert gas tissue pressure graph", align="center"]

Gradient Factor settings strongly affect the calculated ceilings and their
depths.  For more information about Gradient factors, see the section on
xref:S_GradientFactors[Gradient Factor Preference settings]. The currently
used gradient factors (e.g. GF 35/75) are shown above the depth profile if
the appropriate toolbar buttons are activated.  *N.B.:* The indicated
gradient factors are NOT the gradient factors in use by the dive computer,
but those used by _Subsurface_ to calculate deco obligations during the
dive. For more information external to this manual see:

 ** http://www.tek-dive.com/portal/upload/M-Values.pdf[Understanding M-values by Erik Baker, _Immersed_ Vol. 3, No. 3.]

 ** link:http://www.rebreatherworld.com/general-and-new-to-rebreather-articles/5037-gradient-factors-for-dummies.html[Gradient factors for dummies, by Kevin Watts]


=== The Dive Profile context menu

The context menu for the Dive Profile is accessed by right-clicking while
the mouse cursor is over the Dive Profile panel. The menu allows the
creation of Bookmarks or Gas Change Event markers or manual CCR set-point
changes other than the ones that might have been imported from a Dive
Computer. Markers are placed against the depth profile line and with the
time of the event set by where the mouse cursor was when the right mouse
button was initially clicked to bring up the menu. Gas Change events involve
a selection of which gas is being switched to, the list of choices being
based on the available gases defined in the *Equipment* Tab. Set-point
change events open a dialog allowing to choose the next set-point value. As
in the planner, a set-point value of zero indicates the diver is breathing
from an open circuit system while any non-zero value indicates the use of a
closed circuit rebreather (CCR).  By right-clicking while over an existing
marker a menu appears, adding options to allow deletion of the marker or to
allow all markers of that type to be hidden. Hidden events can be restored
to view by selecting Unhide all events from the context menu.

[[S_InfoBox]]
=== The *Information Box*

The Information box displays a large range of information pertaining to the
dive profile. Normally the Information Box is located to the top left of the
*Dive Profile* panel. If the mouse points outside of the *Dive Profile*
panel, then only the top line of the Information Box is visible (see
left-hand part of figure (*A*) below). The Information Box can be moved
around in the *Dive Profile* panel by click-dragging it with the mouse so
that it is not obstructing important detail. The position of the Information
Box is saved and used again during subsequent dive analyses.

image::images/InfoBox2.jpg["Figure: Information Box", align="center"]

The moment the mouse points inside the *Dive Profile* panel, the information
box expands and shows many data items. In this situation, the data reflect
the time point along the dive profile indicated by the mouse cursor (see
right-hand part of figure (*B*) above where the Information Box reflects the
situation at the position of the cursor [arrow] in that image). Therefore,
moving the cursor in the horizontal direction allows the Information Box to
show information for any point along the dive profile.  In this mode, the
Information Box gives extensive statistics about depth, gas and ceiling
characteristics of the particular dive. These include: Time period into the
dive (indicated by a @), depth, cylinder pressure (P), temperature,
ascent/descent rate, surface air consumption (SAC), oxygen partial pressure,
maximum operating depth, equivalent air depth (EAD), equivalent narcotic
depth (END), equivalent air density depth (EADD), decompression requirements
at that instant in time (Deco), time to surface (TTS), the calculated
ceiling, as well as the calculated ceiling for several Bühlmann tissue
compartments.

The user has control over the display of several statistics, represented as
four buttons on the left of the profile panel. These are:

[icon="images/icons/MOD.jpg"]
[NOTE]
Clicking this button causes the Information Box to display the *Maximum
Operating Depth (MOD)* of the dive, given the gas mixture used. MOD is
dependent on the oxygen concentration in the breathing gas.  For air (21%
oxygen) it is around 57 m if a maximum pO~2~ of 1.4 is specified in the
*Preferences* section (select _File_ -> Preferences -> Graph_ and edit the
text box _Max pO~2~ when showing MOD_.  Below the MOD there is a markedly
increased risk of exposure to the dangers associated with oxygen toxicity.

[icon="images/icons/NDL.jpg"]
[NOTE]
Clicking this button causes the Information Box to display the *No-deco
Limit (NDL)* or the *Total Time to Surface (TTS)*. NDL is the time duration
that a diver can continue with a dive, given the present depth, that does
not require decompression (that is, before an ascent ceiling appears). Once
one has exceeded the NDL and decompression is required (that is, there is an
ascent ceiling above the diver, then TTS gives the number of minutes
required before the diver can surface. TTS includes ascent time as well as
decompression time.

[icon="images/icons/SAC.jpg"]
[NOTE]
Clicking this button causes the Information Box to display the *Surface Air
Consumption (SAC)*.  SAC is an indication of the surface-normalised
respiration rate of a diver. The value of SAC is less than the real
respiration rate because a diver at 10m uses breathing gas at a rate roughly
double that of the equivalent rate at the surface. SAC gives an indication
of breathing gas consumption rate independent of the depth of the dive so
that the respiratory rates of different dives can be compared. The units for
SAC is litres/min or cub ft/min.

[icon="images/icons/EAD.jpg"]
[NOTE]
Clicking this button displays the *Equivalent Air Depth (EAD)* for nitrox
dives as well as the *Equivalent Narcotic Depth (END)* for trimix
dives. These are numbers of importance to divers who use breathing gases
other than air. Their values are dependent on the composition of the
breathing gas.  The EAD is the depth of a hypothetical air dive that has the
same partial pressure of nitrogen as the current depth of the nitrox dive at
hand. A nitrox dive leads to the same decompression obligation as an air
dive to the depth equaling the EAD. The END is the depth of a hypothetical
air dive that has the same sum of partial pressures of the narcotic gases
nitrogen and oxygen as the current trimix dive. A trimix diver can expect
the same narcotic effect as a diver breathing air diving at a depth equaling
the END.

Figure (*B*) above shows an information box with a nearly complete set of
data.

[[S_gas_pressure_graph]]
==== The Gas Pressure Bar Graph

On the left of the *Information Box* is a vertical bar graph indicating the
pressures of the nitrogen (and other inert gases, e.g. helium, if
applicable) that the diver was inhaling _at a particular instant during the
dive_, indicated by the position of the cursor on the *Dive Profile*. The
drawing on the left below indicates the meaning of the different parts of
the Gas Pressure Bar Graph.

image::images/GasPressureBarGraph.jpg["FIGURE:Gas Pressure bar Graph", align="center"]

- The light green area indicates the total gas, with the top margin of the
  light green area indicating the total gas pressure inhaled by the diver and
  measured from the bottom of the graph to the top of the light green
  area. This pressure has a _relative_ value in the graph and does not
  indicate absolute pressure.

- The horizontal black line underneath the light green margin indicates the
  equilibrium pressure of the inert gases inhaled by the diver, usually
  nitrogen. In the case of trimix, it is the pressures of nitrogen and helium
  combined. In this example, the user is diving with EAN32, so the inert gas
  pressure is 68% of the distance from the bottom of the graph to the total
  gas pressure value.

- The dark green area at the bottom of the graph represents the pressures of
  inert gas in each of the 16 tissue compartments, following the Bühlmann
  algorithm, the fast tissues being on the left hand side.

- The top black horizontal line indicates the gradient factor that applies to
  the depth of the diver at the particular point on the *Dive Profile*. The
  gradient factor shown is an interpolation between the FGLow and GFHigh
  values specified in the Graph tab of the *Preferences Panel* of
  *Subsurface*.

- The bottom margin of the red area in the graph indicates the Bühlman-derived
  M-value, that is the pressure value of inert gases at which bubble formation
  is expected to be severe, resulting in decompression sickness.

These five values are indicated on the left in the graph above. The way the
Gas Pressure Bar Graph changes during a dive is indicated on the right hand
side of the above figure for a diver using EAN32.

- Graph *A* indicates the situation at the start of a dive with diver at the
  surface. The pressures in all the tissue compartments are still at the
  equilibrium pressure because no diving has taken place.

- Graph *B* indicates the situation after a descent to 30 meters. Few of the
  tissue compartments have had time to respond to the descent, their gas
  pressures being far below the equilibrium gas pressure.

- Graph *C* represents the pressures after 30 minutes at 30 m. The fast
  compartments have attained equilibrium (i.e. they have reached the hight of
  the black line indicating the equilibrium pressure). The slower compartments
  (towards the right) have not reached equilibrium and are in the process of
  slowly increasing in pressure.

- Graph *D* shows the pressures after ascent to a depth of 4.5 meters. Since,
  during ascent, the total inhaled gas pressure has decreased strongly from 4
  bar to 1.45 bar, the pressures in the different tissue compartments now
  exceed that of the total gas pressure and approaches the gradient factor
  value (i.e.  the top black horizontal line). Further ascent will result in
  exceeding the gradient factor value (GFHigh), endangering the diver.

- Graph *E* indicates the situation after remaining at 4.5 meters for 10
  minutes. The fast compartments have decreased in pressure. As expected, the
  pressures in the slow compartments have not changed much.  The pressures in
  the fast compartments do not approach the GFHigh value any more and the
  diver is safer than in the situation indicated in graph *D*.



== Organising the logbook (Manipulating groups of dives)

=== The Dive List context menu

Several actions on either a single dive or a group of dives can be performed
using the Dive List Context Menu, found by selecting either a single dive or
a group of dives and then right-clicking.

image::images/ContextMenu.jpg["Figure : Menu contextuel",align="center"] #
NEEDS REPLACEMENT

The context menu is used in many manipulations described below.

==== Customising the columns showed in the *Dive List* panel

image::images/DiveListOptions.jpg["Example: Dive list info options", align="center"]

The default information in the *Dive List* includes, for each dive,
Dive_number, Date, Rating, Dive_depth, Dive_duration and Dive_location. This
information can be controlled and changed by right-clicking on the header
bar of the *Dive List*. For instance, a right-click on the 'Date' header
brings up a list of items that can be shown in the dive list (see
above). Select an item to be shown in the *Dive List* or to be deleted from
the dive list (reflected by the check symbols) and the list is immediately
updated. Preferences for information shown in the *Dive List* are saved and
used when _Subsurface_ is re-opened.

[[S_Renumber]]
=== Renumbering the dives

Dives are normally numbered incrementally from non-recent dives (low
sequence numbers) to recent dives (having the highest sequence numbers). The
numbering of the dives is not always consistent. For instance, when
non-recent dives are added to the dive list the numbering does not
automatically follow on because of the dives that are more recent in
date/time than the newly-added dive with an older date/time. Therefore, one
may sometimes need to renumber the dives.  This is performed by selecting
(from the Main Menu) _Log -> Renumber_. Users are given a choice with
respect to the lowest sequence number to be used.  Completing this operation
results in new sequence numbers (based on date/time)  for the dives in the
*Dive List* panel.

One can also renumber a few selected dives in the dive list. Select the
dives that need renumbering. Right-click on the selected list and use the
Dive List Context Menu to perform the renumbering. A popup window appears
requiring the user to specify the starting number for the renumbering
process.

[[S_Group]]
=== Grouping dives into trips and manipulating trips

For regular divers, the dive list can rapidly become very long. _Subsurface_
can group dives into _trips_. It performs this by grouping dives that have
date/times not separated in time by more than two days, thus creating a
single heading for each diving trip represented in the dive log. Below is an
ungrouped dive list (*A*, on the left) as well as the corresponding grouped
dive list comprising five dive trips (*B*, on the right):

image::images/Group2.jpg["Figure: Grouping dives", align="center"]

Grouping into trips allows a rapid way of accessing individual dives without
having to scan a long lists of dives. In order to group the dives in a dive
list, (from the Main Menu) select _Log -> Autogroup_. The *Dive List* panel
now shows only the titles for the trips.

==== Editing the title and associated information for a particular trip

Normally, in the dive list, minimal information is included in the trip
title.  More information about a trip can be added by selecting its trip
title from the *Dive List*. This shows a *Trip Notes* tab in the *Notes*
panel. Here one can add or edit information about the date/time, the trip
location and any other general comments about the trip as a whole (e.g. the
dive company that was dived with, the general weather and surface conditions
during the trip, etc.).  After entering this information, select *Save* from
the buttons at the top right of the *Trip Notes* tab. The trip title in the
*Dive List* panel should now reflect the edited information.

==== Viewing the dives during a particular trip

Once the dives have been grouped into trips, users can expand one or more
trips by clicking the arrow-head on the left of each trip title. This
expands the selected trip, revealing the individual dives performed during
the trip.

==== Collapsing or expanding dive information for different trips

After selecting a particular trip in the dive list, the context menu allows
several possibilities to expand or collapse dives within trips. This
includes expanding all trips and collapsing all trips.

==== Merging dives from more than one trip into a single trip

After selecting a trip title, the context menu allows the merging of trips
by either merging the selected trip with the trip below or with the trip
above. (Merge trip with trip below; Merge trip with trip above)

==== Splitting a single trip into more than one trip

If a trip includes ten dives, the user can split this trip into two trips
(trip 1: top 4 dives; trip 2: bottom 6 dives) by selecting and
right-clicking the top four dives. The resulting context menu allows the
user to create a new trip by choosing the option *Create new trip
above*. The top four dives are then grouped into a separate trip. The
figures below shows the selection and context menu on the left (A) and the
completed action on the right (B):

image::images/SplitDive3a.jpg["FIGURE: Split a trip into 2 trips", align="center"]

=== Manipulating single dives

==== Delete a dive from the dive log

Dives can be permanently deleted from the dive log by selecting and
right-clicking them to bring up the context menu, and then selecting *Delete
dive(s)*. Typically this would apply to a case where a user wishes to delete
workshop calibration dives of the dive computer or dives of extremely short
duration.

==== Unlink a dive from a trip

Users can unlink dives from the trip to which they belong. In order to do
this, select and right-click the relevant dives to bring up the context
menu. Then select the option *Remove dive(s)  from trip*. The dive(s) now
appear immediately above or below the trip to which they belonged, depending
on the date and time of the unliked dive.

==== Add a dive to the trip immediately above

Selected dives can be moved from the trip to which they belong and placed
within a separate trip. To do this, select and right-click the dive(s) to
bring up the context menu, and then select *Create new trip above*.

==== Shift the start time of dive(s)

Sometimes it is necessary to adjust the start time of a dive. This may apply
to situations where dives are performed in different time zones or when the
dive computer has an erroneous time. In order to do this, select and
right-click the dive(s) to be adjusted. This action brings up the context
menu on which the *Shift times* option should be selected. User must then
specify the time (in hours and minutes) by which the dives should be
adjusted and click on the option indicating whether the time adjustment
should be ealier or later.

==== Merge dives into a single dive

Sometimes a dive is briefly interrupted, e.g. if a diver returns to the
surface for a few minutes, resulting in two or more dives being recorded by
the dive computer and appearing as different dives in the *Dive List*
panel. Users can merge these dives onto a single dive by selecting the
appropriate dives, right-clicking them to bring up the context menu and then
selecting *Merge selected dives*. It may be necessary to edit the dive
information in the *Notes* panel to reflect events or conditions that apply
to the merged dive. The figure below shows the depth profile of two dives
that were merged:

image::images/MergedDive.png["Example: Merged dive", align="center"]

==== Undo dive manipulations

Important actions on dives or trips, described above, can be undone or
redone.  This includes: _delete dives_, _merge dives_, _renumber dives_ and
_shift dive times_.  To do this after performing any of these actions, from
the *Main Menu* select _Edit_. This brings up the possibility to _Undo_ or
_Redo_ an action.


[[S_Filter]]
=== Filtering the dive list

The dives in the *Dive List* panel can be filtered, that is, one can select
only some of the dives based on their attributes, e.g. dive tags, dive site,
dive master, buddy or protective clothing. For instance, filtering allows
one to list the deep dives at a particular dive site, or otherwise the cave
dives with a particular buddy.

To open the filter, select _Log -> Filter divelist_ from the main menu. This
opens the _Filter Panel_ at the top of the _Subsurface_ window. Three icons
are located at the top right hand of the filter panel (see image below). The
_Filter Panel_ can be reset (i.e. all current filters cleared) by selecting
the *yellow angled arrow*. The _Filter Panel_ may also be minimised by
selecting the *green up-arrow". When minimised, only these three icons are
shown.  The panel can be maximised by clicking the icon that minimised the
panel. The filter may also be reset and closed by selecting the *red button*
with the white cross.

image::images/Filterpanel.jpg["Figure: Filter panel", align="center"]

Four filter criteria may be used to filter the dive list: dive tags, person
(buddy / dive master), dive site and dive suit, each of which is represented
by a check list with check boxes. Above each check list is a second-level
filter tool, allowing the listing of only some of the attributes within that
check list. For instance, typing "_ca_" in the filter textbox above the tags
check list results in the tags check list being reduced to "_cave_" and
"_cavern_". Filtering of the check list enables the rapid finding of search
terms for filtering the dive list.

To activate filtering of the dive list, check at least one check box in one
of the four check lists. The dive list is then shortened to include only the
dives that pertain to the criteria specified in the check lists.  The four
check lists work as a filter with _AND_ operators, Subsurface filters
therefore for _cave_ as a tag AND _Joe Smith_ as a buddy; but the filters
within a category are inclusive - filtering for _cave_ and _boat_ shows
those dives that have either one OR both of these tags.

[[S_ExportLog]]
== Exporting the dive log or parts of the dive log

There are two routes for the export of dive information from Subsurface:

- Exporter les informations de plongée vers _Facebook_

- xref:S_Export_other[Exporter des informations de plongée vers d'autres
  destinations ou formats]

[[S_facebook]]
=== Export des informations de plongée vers _Facebook_

L'export des plongées vers _Facebook_ est géré différemment des autres types
d'export car une connexion vers _Facebook_ est nécessaire, nécessitant un
identifiant et un mot de passe. À partir du menu principal, si vous
sélectionnez _Fichier -> Préférences -> Facebook_, un écran de connexion est
présenté (voir l'image *A* sur la gauche, ci dessous). Entrez vos
identifiant et mot de passe _Facebook_. Une fois connecté à _Facebook_, le
panneau de l'image *B* ci dessous est présenté, avec un bouton _Déconnecter
de Facebook_ pour fermer la connexion _Facebook_.

image::images/facebook1_f20.jpg["Figure: Facebook login", align="center"]

Une fois qu'une connexion à _Facebook_ est établie, transférer un profil de
plongée vers _Facebook_ est facile. Une icône _Facebook_ apparait dans le
panneau *Notes* de _Subsurface_ (voir l'image *A* ci-dessous). Assurez-vous
que la plongée à transférer est affichée dans le panneau *Profil de plongée*
de _Subsurface_. Sélectionnez l'icône _Facebook_ et une fenêtre s'affiche,
pour déterminer quelles informations seront transférées avec le profil de
plongée (voir l'image *B* ci-dessous). Pour transférer un profil de plongée
vers _Facebook_, le nom d'un album _Facebook_ doit être fourni. Les cases à
cocher sur la partie gauche permettent de sélectionner des informations
supplémentaires à transférer avec le profil de plongée. Ces informations
sont affichées dans le champs de texte sur la partie droite du
panneau. (voir l'image *B* ci dessous). Vous pouvez facilement modifier le
message qui sera envoyé avec le profil de plongée. Une fois les informations
supplémentaires ajoutées et vérifiées, sélectionner le bouton _OK_ qui lance
le transfert vers _Facebook_. Après un moment, une fenêtre apparait
indiquant le succès du transfert.

À la fois l'album créé et la publication sur votre ligne temporelle seront
marquées comme privés. Pour que vos amis puissent voir la publication,
modifier les permissions à partir d'une connexion Facebook standard depuis
un navigateur ou l'application Facebook. Malgré que cela soit une étape
supplémentaire, c'est la meilleure solution pour éviter d'avoir des
publications non désirées sur votre ligne temporelle publique.

image::images/facebook2_f20.jpg["Figure: Facebook login", align="center"]

Si besoin, fermer la connexion _Facebook_ en fermant _Subsurface_ ou en
sélectionnant _Fichier -> Préférences -> Facebook, à partir du menu
principal et en cliquant sur le bouton approprié dans le panneau des
préférences Facebook.

[[S_Export_other]]
=== Export dive information  to other destinations or formats
For non-_Facebook exports_, the export function can be reached by selecting
_File -> Export_, which brings up the Export dialog. This dialog always
gives two options: save ALL dives, or save only the dives selected in *Dive
List* panel of _Subsurface_. Click the appropriate radio button (see images
below).

image::images/Export_f20.jpg["Figure: Export dialog", align="center"]

A dive log or part of it can be saved in three formats:

* _Subsurface XML_ format. This is the native format used by _Subsurface_.

* Universal Dive Data Format (_UDDF_). Refer to _http://uddf.org_ for more
  information.  UDDF is a generic format that enables communication among many
  dive computers and computer programs.

* _Divelogs.de_, an Internet-based dive log repository. In order to upload to
  _Divelogs.de_, one needs a user-ID as well as a password for
  _Divelogs.de_. Log into _http://en.divelogs.de_ and subscribe to this
  service in order to upload dive log data from _Subsurface_.

* _DiveShare_ is also a dive log repository on the Internet focusing on the
  recreational dives. In order to upload dives one has to provide a used ID,
  so registration with _http://scubadiveshare.com_ is required.

* _CSV dive details_, that includes the most critical information of the dive
  profile. Included information of a dive is: dive number, date, time, buddy,
  duration, depth, temperature and pressure: in short, most of the information
  that recreational divers enter into handwritten log books.

* _CSV dive profile_, that includes a large amount of detail for each dive,
  including the depth profile, temperature and pressure information of each
  dive.

* _HTML_ format, in which the dive(s) are stored in HTML files, readable with
  an Internet browser. Most modern web browsers are supported, but JavaScript
  must be enabled. The HTML export cannot be changed or edited.  It contains
  most of the information recorded in the dive log. However, it does not show
  the calculated values in the *Dive Profile* panel, e.g. calculated cylinder
  pressure, gas pressures and MOD. The HTML export contains a search option to
  search the dive log. HTML export is specified on the second tab of the
  Export dialog (image *B* above). A typical use of this option is to export
  all one's dives to a smartphone or a tablet where it would serve as a very
  portable record of dives useful for dive companies that wish to verify the
  dive history of a diver, often doing away with the need to carry one's
  original logbook with one when doing dives with dive companies.

* _Worldmap_ format, an HTML file with a world map upon which each dive and
  some information about it are indicated. This map is not editable. If one
  selects any of the dive sites on the map, a summary of the dive is available
  in text, as shown in the image below.

image::images/mapview_f20.jpg["Figure: HTML Map export view", align="center"]


* _Image depths_, which creates a text file that contains the file names of
  all photos or images attached to any of the selected dives in the _Dive
  List_, together with the depth under water where of each of those photos
  were taken.

* _General Settings_, under the HTML tab, provides the following options:

** Subsurface Numbers: if this option is checked, the dive(s) are exported with the
   numbers associated with them in Subsurface, Otherwise the dive(s) will be numbered
   starting from 1.
** Export Yearly Statistics: if this option is checked, a yearly statistics table will
   be attached to the HTML exports.
** Export List only: a list of dives only (date, time, depth, duration) will be exported
   and the detailed dive information, e.g. dive profile, will not be available.

* Under _Style Options_ some style-related options are available like font
  size and theme.

Export to other formats can be achieved through third party facilities, for
instance _www.divelogs.de_.

[[S_Cloud_access]]
== Keeping a _Subsurface_ dive log in the Cloud

For each diver, dive log information is highly important. Not only is it a
record of diving activities for one's own pleasure, but it is important
information required for admission to further training courses or
(sometimes) even diving sites. The security of the dive log is therefore
critical. In order to have a dive log that is resistant to failure of a home
computer hard drive, loss or theft of equipment, the Cloud is an obvious
solution. This also has the added benefit that one can access one's dive log
from anywhere in the world without having to carry it with oneself. For this
reason, facilities such as _divelogs.de_ and _Diving Log_ offer to store
dive log information on the Internet.

_Subsurface_ includes access to a transparently integrated cloud storage
backend that is available to all Subsurface users. Storing and retrieving a
dive log from the cloud is no more difficult than accessing the dives on the
local hard disk.  The only requirement is that one should first register as
a user on the cloud.  To use _Subsurface cloud storage_ , follow these
steps:

=== Create a cloud storage account

** Open the *Network Preferences* by selecting _File_ -> _Preferences_ -> _Network_.
** In the section headed _Subsurface cloud storage_, enter an email address that
   _Su bsurface can use for user registration.
** Enter a novel password that_Subsurface_ will use to store the
  dive log in the cloud.
** Click _Apply_ to send the above email address and password to the
  (remote) cloud server. The server responds by sending a verification PIN to
  the above email address (This is the *only* occasion that _Subsurface_ uses the
  email address provided above). The *Network Preferences* dialog now has a new PIN text
   box, not visible previously.
** Enter the PIN in the corresponding text box in the *Network Preferences* dialog
(this field is only visible while the server is waiting for email
address confirmation)
** Click _Apply_ again. The _Subsurface cloud storage_ account
will be marked as verified and the _Subsurface cloud storage_ service is initialised for use.

=== Using _Subsurface cloud storage_

** Once the cloud storage has been initialised, two new items appear in the
   _File_ menu of the main menu system: _Open cloud storage_ and _Save to cloud storage_.
These options allow the user to load and save data to the _Subsurface
cloud storage_ server.
** In the _Defaults Preferences_ tab, one can select to use the _Subsurface cloud
storage_ data as one's default data file by checking the check box marked _Cloud storage default file_.
 This means that the data from
the _Subsurface cloud storage_ is loaded when _Subsurface_ starts ans saved there when one closes _Subsurface_.

** _Subsurface_ keeps a local copy of the data and the cloud facility remains fully
functional even if used while disconnected to the Internet. _Subsurface_ simply synchronises the
data with the cloud server the next time ithe program is used while the computer is
connected to the Internet.

=== Web access to _Subsurface cloud storage_

One of the nice side benefits of using _Subsurface cloud storage_ is that
one can also access one's dive data from any web browser. Simply open
https://cloud.subsurface-divelog.org[_https://cloud.subsurface-divelog.org_],
log in with the same email and password, and you can see an HTML export of
the last dive data that was synced to the _Subsurface cloud storage_. The
dive information that is shown is only the contents of the recorded dive
logs, NOT the calculated values shown in the *Profile* panel, including some
cylinder pressures, deco ceilings and O~2~/He/N~2~ partial pressures.

=== Other cloud services

If one prefers not to use the integrated cloud storage of dive logs (and
don't need the web access), it is also simple to store dive logs in the
cloud using several of the existing facilities on the Internet.  For
instance http://www.dropbox.com/[_Dropbox_] offers a free application that
allows files on the Dropbox servers to be seen as a local folder on one's
desktop computer.

image::images/Cloud.jpg["FIGURE: Dropbox folder", align="center"]

The _Dropbox_ program creates a copy of the _Dropbox_ Internet Cloud content
on one's desktop computer. When the computer is connected to the Internet,
the Internet content is automatically updated. Therefore both the _Open_ and
_Save_ of dive logs are done using the local copy of the dive log in the
local _Dropbox_ folder, so there's no need for a direct internet
connection. If the local copy is modified, e.g. by adding a dive, the remote
copy in the _Dropbox_ server in the Cloud will be automatically updated
whenever Internet access is available.

In this way a dive log in one's _Dropbox_ folder can be accessed seamlessly
from the Internet and can be accessed from any place with Internet
access. Currently there are no costs involved for this service. Dropbox
(Windows, Mac and Linux) can be installed by accessing the
http://www.dropbox.com/install[_Install Page on the Dropbox website_]
Alternatively one can use _Dropbox_ as a mechanism to backup one's dive
log. To Store a dive log on _Dropbox_, select _File -> Save as_ from the
_Subsurface_ main menu, navigate to the _Dropbox_ folder and select the
_Save_ button. To access the dive log in _Dropbox_, select _File -> Open
Logbook_ from the _Subsurface_ main menu and navigate to the dive log file
in the _Dropbox_ folder and select the _Open_ button.

Several paid services exist on the Internet (e.g. Google, Amazon) where the
same process could be used for the Cloud-based storage of dive logs.


[[S_PrintDivelog]]
== Printing a dive log

_Subsurface_ provides a simple and flexible interface to print a whole dive log or only a few selected dives.
  Pre-installed templates or a custom written template can be used to choose where the data are fitted into the page.

Before printing, two decisions are required:

- Should the whole dive log be printed or only part of it? If only part of the
  dive log is required, then select the required dives from the *Dive List*
  panel.
- If the dive profiles needs printing, what gas partial pressure information
  should be shown? Select the appropriate toggle-buttons on the button bar to
  the left of the *Dive Profile* panel.

If _File -> Print_ is selected from the Main menu, the the dialogue below
(image *A*) appears. Three specifications are needed to achieve the desired
information and page layout:

image::images/Print1_f22.jpg["FIGURE: Print dialogue", align="center"]

1. Under _Print type_ select one of two options:

- _Dive list print_: Print dives from the *Dive List* panel with profiles and
  other information.
- _Statistics print_: Print yearly statistics of the dives.

2. Under _Print options_ select:

- Printing only the dives selected from the dive list prior to activating the
  print dialogue by checking the box _Print only selected dives_. If this
  check box is *not* checked all dives in the *Dive List* panel are printed.
- Printing in colour, achieved by checking the box with _Print in colour_. If
  this check box is not checked, printing is in monochrome (grey scale).

Under _Template_ select a template to be used as the page layout. There are
several templates (see image *B*, above).

- _Table_: This prints a summary table of all dives selected (see below).

image::images/Print_summarylist_f22.jpg["FIGURE: Print summary table", align="center"]

- _Flow layout_: Print the text associated with each diev without printing the
  dive profiles
     of each dive (see below):

image::images/Print_flow_layout_f22.jpg["FIGURE: Print flow layout", align="center"]

- _One Dive_: Print one dive per page, also showing the dive profile (see
  below)

image::images/print2_f22.jpg["FIGURE: Print one dive / page", align="center"]


- _Two Dives_: Print two dives per page, also showing the dive profiles.
- _Six Dives_: Print six dives per page, also showing the dive profiles.
- _Custom_: This option allows customisation of the print contents and
  layout. This is
     discussed at the end of this section.

Users can _Preview_ the printed page by selecting the _Preview_ button on
the dialogue (see image *A* at the start of this section). After preview,
changes to the options in the print dialogue can be made, resulting in a
layout that fits personal taste.

Next, select the _Print_ button (see image *A* at the start of this
section). This activates the regular print dialogue used by the user
operating system, allowing one to choose a printer and to set its properties
(see image below):

image::images/Print_print_f22.jpg["FIGURE: Print one dive / page", align="center"]

Set the print resolution of the printer to an appropriate value by changing
the printer _Properties_. Finally, select the _Print_ button to print the
dives.  Below is a (rather small) example of the output for one particular
page.

image::images/Printpreview.jpg["FIGURE: Print preview page", align="center"]

=== Write a custom printing template (advanced)

Writing a custom template is an effective way to produce highly customized
printouts. Subsurface uses HTML templates to render printing. One can create
a template, export a new template, import an existing template and delete an
existing template by using the appropriate buttons under the _Template_
dropdown list in the print dialogue. See <<S_APPENDIX_E,APPENDIX E>> for
information on how to write or modify a template.

[[S_Configure]]
== Configurer un ordinateur de plongée

_Subsurface_ permet de configurer son ordinateur de plongée. Actuellement,
les familles d'ordinateurs supportés sont Heinrichs-Weikamp (OSTC 2, OSTC 3)
et Suunto Vyper (Stinger, Mosquito, D3, Vyper, Vytec, Cobra, Gekko et
Zoop). De nombreux paramètres de ces ordinateurs de plongée peuvent être
lues et modifiées. La première étape est de s'assurer que les pilotes pour
votre ordinateur de plongée sont installés (également nécessaire pour
télécharger les plongées) et que le nom de périphérique de l'ordinateur de
plongée est connu. Voir
<<_appendix_a_operating_system_specific_information_for_importing_dive_information_from_a_dive_computer,ANNEXE
A>> pour plus d'informations sur la manière de procéder.

Une fois que l'ordinateur de plongée est connecté à _Subsurface_,
sélectionner _Fichier -> Configurer l'ordinateur de plongée_, à partir du
menu principal. Fournir le nom du périphérique dans le champ en haut du
panneau de configuration et sélectionner le bon modèle d'ordinateur de
plongée à partir du panneau à gauche (voir l'image ci-dessous).

image::images/Configure_dc_f20.jpg["FIGURE: Configure dive computer", align="center"]

En utilisant les boutons appropriés du panneau de configuration, les actions
suivantes peuvent être réalisées :

 - *Récupérer les détails disponibles*. Cela charge la configuration existante à partir de l'ordinateur de plongée
   dans _Subsurface_, en l'affichant dans le panneau de configuration.
 - *Enregistrer les modifications sur le périphérique*. Cela change la configuration de l'ordinateur
   de plongée pour correspondre aux informations affichées dans le panneau de configuration.
 - *Sauvegarder*. Cela enregistre la configuration dans un fichier. _Subsurface_ demande
   l'emplacement et le nom du fichier pour enregistrer les informations.
 - *Restaurer une sauvegarde*. Cela charge les informations à partir d'un fichier de sauvegarde et l'affiche
   dans le panneau de configuration.
 - *Mettre à jour le firmware*. Si un nouveau firmware est disponible pour l'ordinateur de plongée,
   il sera chargé dans l'ordinateur de plongée.


[[S_Preferences]]
== Setting user _Preferences_ for _Subsurface_

There are several settings within _Subsurface_ that the user can
specify. These are found when selecting _File -> Preferences_. The settings
are performed in five groups: *Defaults*, *Units*, *Graph*, *Language* and
*Network*. All five sections operate on the same principles: the user must
specify the settings that are to be changed, then these changes are saved
using the *Apply* button. After applying all the new settings users can then
leave the settings panel by selecting *OK*.

=== Defaults

There are several settings in the *Defaults* panel:

image::images/Pref1_f20.jpg["FIGURE: Preferences defaults page", align="center"]

  ** *Lists and tables*: Here one can specify the font type and font size of the
     *Dive Table* panel. By decreasing the font size of the *Dive Table*, users can see more dives on a screen.

  ** *Dives*: For the _Default Dive File_ one need to specify the directory and
     file name of one's
     electronic dive log book. This is a file with filename extension .xml. When
     launched, _Subsurface_ will automatically load the specified dive log book.

  ** *Display invalid*:  Dives can be marked as invalid (when a user wishes to hide
     dives that he/she don't consider valid dives, e.g. pool dives, but still want to
     keep them in the dive log). This controls whether those dives are displayed in
     the dive list.

  ** *Default cylinder*: Here users can specify the default cylinder listed in
     the *Equipment* tab of the *Notes* panel.

  ** *Animations*: Some actions in showing the dive profile are performed using
     animations. For instance, the axis values for depth and time change from dive to
     dive. When viewing a different dive, these changes in axis characteristics do not
     happen instantaneously, but are animated. The _Speed_ of animations can be controlled
     by setting this slider
     with faster animation speed to the left, with a 0 value representing no animation
     at all.

  ** *Subsurface web service*: When one subscribes to the <<S_Companion,Subsurface web service>>, a very
     long and hard-to-remember userID is issued. This is the place to save that userID. By
     checking the option _Save User ID locally?_, one ensures that a local copy of that userID
     is saved.

  ** *Clear all settings*: As indicated in the button below this heading, all settings are
     cleared and set to default values.

=== Units
image::images/Pref2_f20.jpg["FIGURE: Preferences Units page", align="center"]

Here user can choose between metric and imperial units of depth, pressure,
volume, temperature and mass. By selecting the Metric or Imperial radio
button at the top, users can specify that all units are in the chosen
measurement system.  Alternatively, if one selects the *Personalise* radio
button, units can be selected independently, with some units in the metric
system and others in imperial.

=== Graph
[[S_CCR_options]]
image::images/Pref3_f20.jpg["FIGURE: Preferences Graph page", align="center"]

[[S_GradientFactors]]
This panel allows two type of selections:

*Show*: Here users can specify the amount of information shown as part of
the dive profile:
** Thresholds: _Subsurface_ can display the nitrogen, oxygen and the helium partial pressures during
   the dive. These are enabled using the toolbar on the left hand side of the *Dive Profile*
   panel. For each of these graphs users can specify a threshold value on the right-hand side of the
   Preferences panel. If any of the graphs go above this threshold level, the graph is
   highlighted in red, indicating that the threshold has been exceeded.

** _Draw dive computer reported ceiling red_: This checkbox allows exactly what it says.
   Not all dive computers report ceiling values. If the dive computer does report it, it may differ
   from the ceilings calculated by _Subsurface_. This is because of the different algorithms and gradient factors available for calculating ceilings, as well as the dynamic way that a
   dive computer can calculate ceilings during a dive.

** _Show unused cylinders in Equipment Tab_: This checkbox allows display of information about unused cylinders when viewing the *Equipment Tab*. Conversely, if this box is not checked, and any cylinders entered using the *Equipment Tab* are not used (e.g. there was no gas switch to such a cylinder), then these cylinders are omitted from that list.

[[GradientFactors_Ref]]
** _Show average depth_: Activating this checkbox causes _Subsurface_ to draw a grey line across
   the dive profile, indicating the mean depth of the dive up to a particular point in time during
   that dive. Normally this is a u-shaped line indicating the deepest average depth just before the
   ascent.

* *Misc*:

** Gradient Factors:* Here users can set the _gradient factors_ used while diving. GF_Low is
   the gradient factor at depth and GF_High is used just below the surface.
   At intermediate depths gradient factors between GF_Low and GF_High are used.
   Gradient factors add conservatism to the nitrogen exposure during a dive, in a
   similar way that many dive computers have a conservatism setting. The lower
   the value of a gradient factor, the more conservative the calculations are with
   respect to nitrogen loading and the deeper the ascent ceilings are. Gradient
   factors of 20/60 are considered conservative and values of 60/90 are considered
   harsh. Checking *GFLow at max depth* box causes GF_Low to be used at the
   deepest depth of a dive. If this box is not checked, GF_Low is applied at
   all depths deeper than the first deco stop. For more information see:

 *** http://www.tek-dive.com/portal/upload/M-Values.pdf[Understanding M-values by Erik Baker, _Immersed_ Vol. 3, No. 3.]

 *** link:http://www.rebreatherworld.com/general-and-new-to-rebreather-articles/5037-gradient-factors-for-dummies.html[Gradient factors for dummies, by Kevin Watts]

 ** _CCR: Show setpoints when viewing pO2:_ With this checkbox ativated, the pO~2~
    graph on the dive profile has an overlay in red which inticates the CCR setpoint
    values. See the section on xref:S_CCR_dives[Closed Circuit Rebreather dives].

 ** _CCR: Show individual O~2~ sensor values when viewing pO~2~:_ Show the pO~2~
    values associated with each of the individual oxygen sensors of a CCR system.
    See the section on xref:S_CCR_dives[Closed Circuit Rebreather dives].

 *  *Configuring dive planning using rebreather equipment:*

 ** _Default CCR setpoint for dive planning:_ Specify the O~2~ setpoint for a
    CCR dive plan. This determines the pO~2~ that will be maintained
    during a particular dive. This is the setpoint that is used at the start
    of any CCR dive. Setpoint changes during the dive can be added via the
    profile context menu.

 ** _pSCR O~2~ metabolism rate:_ For a semiclosed rebreather (pSCR) system, this is the
    volume of oxygen used by a diver each minute. Set this value for pSCR dive planning
    and decompression calculations.

 ** _pSCR ratio:_ For pSCR equipment the dump ratio is the ratio of gas released to the
    environment to that of the gas recirculated to the diver. Set this value for a
    pSCR dive plan.


=== Language
Choose a language that _Subsurface_ will use.

image::images/Pref4_f20.jpg["FIGURE: Preferences Language page", align="center"]

A checkbox allows one to use the _System Default_ language which in most
cases will be the correct setting; with this _Subsurface_ simply runs in the
same language / country settings as the underlying OS. If this is for some
reason undesirable users can uncheck this checkbox and pick a language /
country combination from the list of included localizations. The _Filter_
text box allows one to list similar languages. For instance there are
several system variants of English or French. This particular preference
requires a restart of _Subsurface_ to take effect.

=== Network
This panel facilitates communication between _Subsurface_ and data sources
on the Internet.

image::images/Pref5_f20.jpg["FIGURE: Preferences Network page", align="center"]

This is important, for instance, when _Subsurface_ needs to communicate with
Internet services such as the <<S_Companion,_Subsurface Companion app_>> or
data export/import from _Divelogs.de_. These Internet requirements are
determined by one's type of connection to the Internet and by the Internet
Service Provider (ISP) used.  One's ISP should provide the appropriate
information.  If a proxy server is used for Internet access, the appropriate
information needs to be provided here. The type of proxy needs to be
selected from the dropdown list.  after which the IP address of the host and
the appropriate port number should be provided. If the proxy server uses
authentication, the appropriate userID and password also needs to be
provided so that _Subsurface_ can automatically pass through the proxy
server to access the Internet.

=== Accès Facebook
Ce panneau vous permet de vous connecter à votre compte Facebook pour
transférer des informations de Subsurface vers Facebook.

image::images/Pref6_f20.jpg["FIGURE: Facebook login panel", align="center"]

Si un identifiant Facebook et un mot de passe valides ont été fournis, une
connexion vers Facebook est créée. Cette connexion est fermée lorsque
Subsurface est fermé. Pour le moment, la case à cocher nommée "Conserver ma
connexion à Subsurface", sur l'écran de connexion, n'a aucun
effet. Reportez-vous à la section xref:S_facebook[Export des profils de
plongée vers Facebook] pour plus d'informations.

[[S_DivePlanner]]
== The _Subsurface_ dive planner
Dive planning is an advanced feature of _Subsurface_, accessible by
selecting _Log -> Plan Dive_ from the main menu. It allows calculation of
nitrogen load during a dive by using the Bühlmann ZH-L16 algorithm with the
addition of gradient factors as implemented by Erik Baker.

****
[icon="images/icons/warning2.png"]
[WARNING]

The _Subsurface_ dive planner IS CURRENTLY EXPERIMENTAL and assumes the user
is already familiar with the _Subsurface_ user interface. It is explicitly
used under the following conditions:

- The user is conversant with dive planning and has the necessary training to
  perform dive planning.
- The user plans dives within his/her certification limits.
- Dive planning makes large assumptions about the characteristics of the
  _average person_ and cannot compensate for individual physiology or health
  or personal history or life style characteristics.
- The safety of a dive plan depends heavily on the way in which the planner is
  used.
- The user is familiar with the user interface of _Subsurface_.
- A user who is not absolutely sure about any of the above requirements should
  not use this feature.
****

=== The _Subsurface_ dive planner screen

Like the _Subsurface_ dive log, the planner screen is divided into several
sections (see image below). The *setup* parameters for a dive are entered
into the several sections on the left hand side of the screen.  The setup is
divided into several sections: Available Gases, Rates, Planning, Gas Options
and Notes.

At the top right hand is a green *design panel* upon which the profile of
the dive can be manipulated directly by dragging and clicking as explained
below. This feature makes the _Subsurface_ dive planner unique in ease of
use.

At the bottom right is a text panel with a heading of _Dive Plan
Details_. This is where the details of the dive plan are provided in a way
that can easily be copied to other software. This is also where any warning
messages about the dive plan are printed.

image::images/PlannerWindow1_f20.jpg["FIGURE: Dive planner startup window", align="center"]


=== Open circuit dives

-  Towards the centre bottom of the planner (circled in blue in the image
   above) is a dropbox with three options. Select the appropriate one of these:
 ** Open Circuit (the default)
 ** CCR
 ** pSCR

- Choose the Open Circuit option.
- In the top left-hand area of the planning screen, ensure that the constant
  dive parameters are appropriate. These are: Start date and time of the
  intended dive, Atmospheric Pressure and Altitude above sea level of the dive
  site. The atmospheric pressure can also be entered as an altitude in metres,
  assuming a sea-level atmospheric pressure of 1.013 bar.

- In the table labeled _Available Gases_, add the information of the cylinders
  to be used as well as the gas composition within that cylinder. This is done
  in a similar way as for <<S_CylinderData,providing cylinder data for dive
  logs>>. Choose the cylinder type by double clicking the cylinder type and
  using the dropdown list, then specify the work pressure of this cylinder. By
  leaving the oxygen concentration (O2%) filed empty, the cylinder is assumed
  to contain air. Otherwise enter the oxygen and/or helium concentration in
  the boxes provided in this dialogue. Add additional cylinders by using the
  "+" icon to the top righthand of the dialogue.

- The profile of the planned dive can be created in two ways:
 *  Drag the waypoints (the small white circles) on the existing dive profile in
    a way to represent the dive. Additional waypoints can be created by
    double-clicking the existing dive profile. Waypoints can be deleted by
    right-clicking a particular waypoint and selecting the _delete_ item from
    the resulting context menu.
 *  The most efficient way to create a dive profile is to enter the appropriate
    values into the table marked _Dive planner points_. The first line of the
    table represents the duration and the final depth of the descent from the
    surface. Subsequent segments describe the bottom phase of the dive.  The _CC
    set point_ column is only relevant for closed circuit divers.  The ascent is
    usually not specified because this is what the planner is supposed to
    calculate.  Add additional segments to the profile by selecting the "+" icon
    at the top right hand of the table. Segments entered into the _Dive planner
    points_ table automatically appear in the *Dive Profile* diagram.

==== Recreational dives

The _Subsurface_ dive planner allows a sophisticated way of planning
recreational dives, i.e. dives that remain within no-decompression limits.
The dive planner automatically takes into account the nitrogen load incurred
in previous dives. But conventional dive tables are also used in a way that
can take into account previous dives. Why use a dive planner for
recreational dives? Using recreational dive tables, the maximum depth of a
dive is taken into acount. However, few dives are undertaken at a constant
depth corresponding to the maximum depth (i.e. a "square" dive
profile). This means that dive tables overestimate the nitrogen load
incurred during previous dives. The _Subsurface_ dive planner calculates
nitrogen load according to the real dive profiles of all uploaded previous
dives, in a similar way as dive computers calculate nitrogen load during a
dive. This mean that the diver gets 'credit' in terms of nitrogen loading
for not remaining at maximum depth during previous dives, enabling planning
a longer subsequent dive. For the planner to work it is therefore crucial to
upload all previous dives onto _Subsurface_ before performing dive planning.

To plan a dive, the appropriate settings need to be defined.

Ensure that the date and time is set to that of the intended dive. This
allows calculation of the nitrogen load incurred during previous dives.

- Immediately under the heading _Planning_ are two checkboxes _Recreational_
  and _Safety Stop_.  Check these two boxes.

- Then define the cylinder size, the gas mixture (air or % oxygen) and the
  starting cylinder pressure in the top left-hand section of the planner under
  _Available gases_.

- The planner calculates whether the specified cylinder contains enough
  air/gas to complete the planned dive. In order for this to be realistic,
  under _Gas options_, specify an appropriate surface air consumption (SAC)
  rate for _Bottom SAC_. Suitable values are between 15 l/min and 30 l/min,
  with novice divers or difficult dives requiring SAC rates closer to 30l/min.

- Define the amount of gas that the cylinder must have at the end of the
  bottom section of the dive just before ascent. A value of 50 bar is often
  used.

- Define the depth of the dive by dragging the waypoints (white dots) on the
  dive profile or (even better) defining the appropriate depths using the
  table under _Dive planner points_ as desribed under the previous heading. If
  this is a multilevel dive, set the appropriate dive depths to represent the
  dive plan by adding waypoints to the dive profile or by adding appropriate
  dive planner points to the _Dive Planner Points_ table.

- The ascent speed can be changed. The default ascent speeds are those
  considered safe for recreational divers.

The dive profile in the planner indicates the maximum dive time within
no-deco limits using the Bühlmann ZH-L16 algorithm and the gas and depth
settings specified as described above. The _Subsurface_ planner allows rapid
assessment of dive duration as a function of dive depth, given the nitrogen
load incurred during previous dives. The dive plan includes estimates of the
amount of air/gas used, depending on the cylinder settings specified under
_Available gases_. If the initial cylinder pressure is set to 0, the dive
duration shown is the true no-deco limit (NDL) without taking into account
gas used during the dive. If the surface above the dive profile is RED it
means that recreational dive limits are exceeded and either the dive
duration or the dive depth needs to be reduced.

Below is an image of a dive plan for a recreational dive at 30
metres. Although the no-deco limit (NDL) is 23 minutes, the duration of the
dive is limited by the amount of air in the cylinder, reflected by the
information in the text box at the bottom right of the panel that requires
sufficient air for buddy-sharing during the ascent.

image::images/rec_diveplan.jpg["FIGURE: A recreational dive plan: setup", align="center"]

==== Non-recreational open circuit dives, including decompression

Non-recreational dive planning involves exceeding the no-deco limits and/or
using multiple breathing gases.  Such dives are planned in three stages:

*a) Nitrogen management*: This is performed by specifying the rates for descent and ascent,
as well as the deco model (GFLow, GFHigh or Conservatism level) under the headings _Rates_ and _Planning_
to the bottom left of the planning screen. Two deco models are supported the Bühlmann model and the VPM-B
model. Select one of the two models. When selecting the Bühlmann model, the gradient factors (GF_high and GF_low
need to be specified. Initially, the GFHigh and GFLow values in the _Preferences_
panel of _Subsurface_ is used. If these are changed within the planner (see _Gas Options_ within
the planner), the new values are
used without changing the original values in the _Preferences_. Gradient Factor settings strongly affect the calculated ceilings and their depths.
A very low GFLow value brings about decompression stops early on during the dive.
 ** For more information about Gradient factors, see the section on xref:S_GradientFactors[Gradient Factor Preference settings].

If the VPM-B model is selected, the Conservatism_level needs to be specified
on a scale of 0 (least conservative) to 4 (most conservative).  This model
tends to give deco stops at deeper levels than the Beuhlmann model and often
results in slightly shorter dive durations than the Bühlmann model. When
selecting one of these models, keep in mind that they are NOT exact
physiological models but only mathematical models that appear to work in
practice.

For more information external to this manual see:

 * link:http://www.tek-dive.com/portal/upload/M-Values.pdf[Understanding
   M-values by Erik Baker, _Immersed_ Vol. 3, No. 3.]
 * link:http://www.rebreatherworld.com/general-and-new-to-rebreather-articles/5037-gradient-factors-for-dummies.html[Gradient
   factors for dummies, by Kevin Watts]
link:http://www.amazon.com/Deco-Divers-Decompression-Theory-Physiology/dp/1905492073/ref=sr_1_1?s=books&ie=UTF8&qid=1403932320&sr=1-1&keywords=deco+for+divers[_Deco
for Divers_, by Mark Powell (2008). Aquapress] Southend-on-Sea, UK. ISBN 10:
1-905492-07-3.  Un excellent livre non technique qui traite à la fois des
modèles de décompression Bühlmann et VPM-B.

The ascent rate is critical for nitrogen off-gassing at the end of the dive
and is specified for several depth ranges, utilising the average (or mean)
depth as a yardstick. The mean depth of the dive plan is indicated by a
light grey line on the dive profile. Ascent rates at deeper levels are often
in the range of 8-12 m/min, while ascent rates near the surface are often in
the range of 4-9 m/min. The descent rate is also specified. If the option
_Drop to first depth_ is activated, then the descent phase of the planned
dive will be at the maximal descent rate specified in the _Rates_ section of
the dive setup.

*b) Oxygen management*: In the *Gas Options* part of the dive specification, the maximum partial
pressure for oxygen needs to be specified for the
bottom part of the dive (_bottom po2_) as well as for the decompression part of the dive (_deco po2_).
The most commonly
used values are 1.4 bar for the bottom part of the dive and 1.6 bar for any decompression
stages. Normally, a partial pressure of 1.6 bar is not exceeded. PO2 settings and the depth at which switching to a gas takes place can also be edited in the
_Available Gases_ dialog. Normally the planner decides on switching to a new gas when, during
ascent, the partial pressure of the new gas has increased to 1.6 bar.

*c) Gas management*: With open-circuit dives this is a primary consideration. One needs to keep within the limits of the amount of gas within the dive
cylinder(s), allowing for an appropriate margin for a safe return to the surface, possibly
sharing with a buddy. Under the _Gas Options_ heading, specify the best (but conservative) estimate
of your surface-equivalent air consumption (SAC, also termed RMV) in
litres/min (for the time being, only SI units are supported).  Specify the SAC during the
bottom part of the dive (_bottom SAC_) as well as during the decompression or safety stops of the
dive (_deco SAC_). Values of 15-30 l/min are common. For good gas management, a thumbsuck guess
is not sufficient and one needs to
monitor one's gas consumption on a regular basis, dependent on different dive conditions and/or equipment.
The planner calculates the total volume of gas used during the dive and issues a warning
if one exceeds the total amount of gas available. Good practice demands that one does not dive to
the limit of the gas supply but that an appropriate reserve is kept for unforeseen circumstances.
For technical diving, this reserve can be up to 66% of the total available gas.

Now (at last) one can start the detailed time-depth planning of the
dive. _Subsurface_ offers a unique graphical interface for performing this
part of the planning. The mechanics of doing this is similar to
hand-entering a dive profile in the dive log part of _Subsurface_. Upon
activating the planner, a default dive of depth 15 m for 40 min is offered
in the bue design surface to the top right hand of the screen. The white
dots (waypoints) on the profile can be dragged with a mouse. Create more
waypoints by double-clicking on the profile line and ensuring that the
profile reflects the intended dive. Drag the waypoints to represent the
depth and duration of the dive. It is NOt necessary to specify the ascent
part of the dive since the planner calculates this, based on the settings
that have been specified.  If any of the management limits (for nitrogen,
oxygen or gas) is exceeded, the surface above the dive profile changes from
BLUE to RED.

Each waypoint on the dive profile creates a _Dive Planner Point_ in the
table on the left of the dive planner panel. Ensure that the _Used Gas_
value in each row of that table corresponds to one of the gas mixtures
specified in the _Available Gases_ table.  Add new waypoints until the main
features of the dive have been completed, e.g. the bottom time segment and
deep stops (if these are implemented). Leave the remaining waypoints on the
ascent to _Subsurface_. In most cases _Subsurface_ computes additional way
points in order to fulfill decompression requirements for that dive. A
waypoint can be moved by selecting that waypoint and by using the arrow
keys.  The waypoints listed in the _Dive Planner Points_ dialogue can be
edited by hand in order to obtain a precise presentation of the dive
plan. In fact, one can create the whole dive profile by editing the _Dive
Planner Points_ dialog.

Indicate any changes in gas cylinder used by indicating gas changes as
explained in the section <<S_CreateProfile,hand-creating a dive
profile>>. These changes should reflect the cylinders and gas compositions
defined in the table with _Available Gases_.  If two or more gases are used,
automatic gas switches will be suggested during the ascent to the
surface. However, these changes can be deleted by right-clicking the gas
change and by manually creating a gas change by right-clicking on the
appropriate waypoint.

A non-zero value in the "CC set point" column of the table of dive planner
points indicates a valid setpoint for oxygen partial pressure and that the
segment is dived using a closed circuit rebreather (CCR). If the last
manually entered segment is a CCR segment, the decompression phase is
computed assuming the diver uses a CCR with the specified set-point. If the
last segment (however short) is on open circuit (OC, indicated by a zero
set-point) the decompression is computed in OC mode. The planner only
considers gas changes in OC mode.

Below is an example of a dive plan to 45m using EAN26, followed by an ascent
using EAN50 and using the settings as described above.

image::images/DivePlanner2_f20.jpg["FIGURE: Planning a dive: setup", align="center"]

Once the above has been completed, one can save it by clicking the _Save_
button towards the top middle of the planner. The saved dive plan will
appear in the *Dive List* panel of _Subsurface_.

*The dive plan details*

On the bottom right of the dive planner, under _Dive Plan Details_, the
exact details of the dive plan are provided. These details may be modified
by checking any of the options under the _Notes_ section of the dive
planner, immediately to the left of the _Dive Plan Details_. If a _Verbatim
diveplan_ is requested, a detailed sentence-level explanation of the dive
plan is given. If any of the management specifications have been exceeded
during the planning, a warning message is printed underneath the dive plan
information.

If the option _Display segment duration_ is checked, then the duration of
each depth level is indicated in the _Dive Plan Details_. This duration
INCLUDES the transition time to get to that level. However, if the _Display
transition in deco_ option is checked, the transitions are shown separately
from the segment durations at a particular level.

=== Planning pSCR dives

To plan a dive using a passive semi-closed rebreather (pSCR), select _pSCR_ rather than
_Open circuit_ in the dropdown list.
The parameters of the pSCR diver can be set by selecting  _File ->   Preferences ->   Graph_
from the main menu, where the gas consumption calculation takes into account the pSCR dump
ratio (default 10:1) as well as the metabolism rate. The calculation also takes the oxygen drop
accross the mouthpiece of the rebreather into account. If the
pO~2~ drops below what is considered a save value, a warning appears in the _Dive plan
details_. A typical pSCR configuration is with a single cylinder and one or more bail-out
cylinders. Therefore the setup of the _Available gases_ and the _Dive planner points_ tables
are very similar to that of a CCR dive plan, described above. However, no oxygen setpoints
are specified for pSCR dives. Below is a dive plan for a pSCR dive. The dive is comparable
to that of the CCR dive above, but note the longer ascent duration due to the lower oxygen
in the loop due to the oxygen drop across the mouthpiece of the pSCR equipment.

image::images/Planner_pSCR1_f20.jpg["FIGURE: Planning a pSCR dive: setup", align="center"]


=== Planning CCR dives

To plan a dive using a closed circuit rebreather, select the _CCR_ option in
the dropdown list, circled in blue in the image below.

*Available gases*: In the _Available gases_ table, enter the cylinder information for the
diluent cylinder and for any bail-out cylinders. Do NOT enter the information for the oxygen
cylinder since it is implied when the _CCR_ dropdown selection is made.

*Entering setpoints*: Specify a default setpoint in the Preferences tab, by selecting _File ->  Preferences ->  Graph_ from the main menu. All user-entered segments in the _Dive planner points_ table
use the default setpoint value. Then, different setpoints can be specified for dive segments
in the _Dive planner points_ table. A zero setpoint
means the diver bails out to open circuit mode for that segment. The decompression is always calculated
using the setpoint of the last manually entered segment. So, to plan a bail out ascent for a
CCR dive, add a one-minute dive segment to the end with a setpoint value of 0. The decompression
algorithm does not switch deco-gases automatically while in CCR mode (i.e. when a positive setpoint is specified) but, of course, this is calculated for bail out ascents.

The dive profile for a CCR dive may look something like the image below.

image::images/Planner_CCR1_f20.jpg["FIGURE: Planning a CCR dive: setup", align="center"]

Note that, in the _Dive plan details_, the gas consumption for a CCR segment
is not calculated, so gas consumptions of 0 litres are the norm.

[[S_Replan]]
=== Modifying an existing dive plan

Normally, when a dive plan has been saved, it is accessible from the *Dive
List*, like any other dive log. Within the *Dive List* there is not a way to
change a saved dive plan.  To perform changes to a dive plan, select it on
the *Dive List*. Then, in the main menu, select _Log -> Re-plan dive_. This
will open the selected dive plan within the dive planner, allowing changes
to be made and saved as usual.

In addition there is the option "Save new". This keeps the original planned
dive and adds a (possibly modified) copy to the dive list. If that copy is
saved with the same start time as the original, the two dives are considered
two versions of the same dive and do not influence other each during
decompression calculation (see next section).

=== Planning for repetitive dives

Repetitive dives can easily be planned if the dates and start times of the
repetitive dive set is specified appropriately in the top left-hand _Start
Time_ field. _Subsurface_ calculates the gas loading figures correctly and
the effect of the first dive is evaluated on later dives.

If one has just completed a long/deep dive and is planning another dive,
then highlight, in the *Dive List*, the dive that has just been completed
and then activate the planner. Depending on the start time of the planned
dive, the planner takes into account the gas loading incurred during the
completed dive and allows planning within these limitations.

If only a few standard configurations are used (e.g. in GUE), then a
template dive can be created conforming to one of the configurations. If one
now wishes to plan a dive using this configuration, just highlight the
template dive in the *Dive List* and activate the planner: the planner takes
into account the configuration in the highlighted dive.

=== Printing the dive plan

Selecting the _Print_ button in the planner allows printing of the _Dive
Plan Details_ for wet notes. Alternatively one can cut and paste the _Dive
Plan Details_ for inclusion in a text file or word processing document.

Dive plans have many characteristics in common with dive logs (dive profile,
dive notes, etc).  After a dive plan has been saved, the dive details and
gas calculations are saved in the *Notes* tab. While a dive plan is being
designed, it can be printed using the _Print_ button in the dive
planner. This prints the dive details and gas calculations in the _Dive Plan
Details_ panel of the dive planner. However, after the plan has been saved,
it is represented in a way very similar to a dive log and the gas
calculations cannot be accessed in the same way as during the planning
process. The only way to print the dive plan is to use the _File -> Print_
facility on the main menu in the same way as for dive logs or by copy and
paste to a word processor.

== Description des éléments du menu principal de Subsurface

Cette section décrit les fonctions et les opérations des éléments du menu
principal de Subsurface. Plusieurs éléments ci-dessous sont des liens vers
des sections de ce manuel traitant des opérations relatives.

=== Fichier
- <<S_NewLogbook,_Nouveau carnet de plongée_>> - Fermer le carnet de plongée
  actuellement ouvert et supprime toutes les informations de plongées.
- _Ouvrir un carnet de plongée_ - Cela ouvre une fenêtre pour sélectionner le
  carnet de plongée à ouvrir.
- _Sauvegarder_ - Enregistrer le carnet de plongée qui est actuellement
  ouvert.
- _Enregsitrer sous_ - Enregistrer le carnet actuel sous un nom différent.
- _Fermer_ - Fermer le carnet de plongée actuellement ouvert.
- <<S_ExportLog,_Exporter_>> - Exporter le carnet de plongée actuellement
  ouvert (ou les plongées sélectionnées dans le carnet) vers un des nombreux
  formats.
- <<S_PrintDivelog,_Imprimer_>> - Imprimer le carnet de plongée actuellement
  ouvert.
- <<S_FindMovedImages, _Find moved images_>> - If photos taken during dives
  have been moved to
      a different disk or directory, locate them and link them to the appropriate
      dives.
- <<S_Preferences,_Préférences_>> - Définir les  préférences de _Subsurface_.
- <<S_Configure,_Configurer l'ordinateur de plongée_>> - Modifier la
  configuration d'un ordinateur de plongée.
- _Quitter_ - Quitter _Subsurface_.

=== Importer
- <<S_ImportDiveComputer,_Importer depuis un l'ordinateur de plongée_>> -
  Importer des informations de plongées à partir de l'ordinateur de plongée.
- <<Unified_import,_Importer des fichiers de log_>> - Importer des
  informations de plongées à partir d'un fichier d'un format compatible avec
  _Subsurface_.
- <<S_Companion,_Importer les données GPS depis le service web Subsurface_>> -
  Charge les coordonnées GPS à partir de l'application mobile _Subsurface_
  (téléphones et tablettes).
- <<S_ImportingDivelogsDe,_Importer depuis Divelogs.de_>> - Importer des
  informations de plongées à partir de _www.Divelogs.de_.

=== Journal (log)
- <<S_EnterData,_Ajouter une plongée_>> -  Ajouter manuellement une nouvelle
  plongée au panneau de la *liste des plongées*.
- _Edit dive_ - Edit a dive of which the profile was entered by hande and not
  from a dive computer.
- <<S_DivePlanner,_Planifier une plongée_>> - Cette fonctionnalité permet de
  planifier des plongées.
- <<S_Replan,_Modifier la plongée dans le planificateur_>> - Modifier une
  plongée planifiée qui a été enregistrée dans la *liste des plongées*.
- <<S_CopyComponents,_Copier les composants de la plongée_>> - En
  sélectionnant cette option, vous pouvez copier les informations de plusieurs
  champs d'un journal de plongée vers le presse-papier.
- _Coller les composants de la plongée_  - Colle, dans les plongées
  sélectionnées dans la *liste des plongées*, les informations copiées au
  préalable avec l'option _Copier les composants de la plongée_.
- <<S_Renumber,_Renuméroter_>> - Renuméroter les plongées sélectionnées dans
  le panneau de la *liste des plongées*.
- <<S_Group,_Grouper automatiquement_>> - Grouper les plongées du panneau de
  *liste des plongées* dans des voyages de plongées.
- <<S_DeviceNames,_Editer les noms des ordinateurs de plongée_>> - Modifier
  les noms des ordinateurs de plongée pour faciliter vos journaux (logs).
- <<S_Filter,_Filtrer la liste des plongées_>> - Sélectionner seulement
  certaines plongées, à partir de tags ou de critères de plongées.

=== Vue
- <<S_ViewPanels,_Tout_>> - Affiche les quatre panneaux principaux de
  _Subsurface_ simultanément.
- <<S_ViewPanels,_Liste des plongées_>> - Affiche uniquement le panneau de la
  *liste des plongées*.
- <<S_ViewPanels,_Profil_>> - Affiche uniquement le panneau du *profil de la
  plongée*.
- <<S_ViewPanels,_Info_>> - Affiche uniquement le panneau des *notes*.
- <<S_ViewPanels,_Globe_>> - Affiche uniquement le panneau de la *carte
  mondiale*.
- _Statistiques annuelles_  - Affiche par année le résumé des statistiques des
  plongées effectuées.
- _Ordinateur précédent_  - Passer à l'ordinateur de plongée précédent.
- _Ordinateur suivant_  - Passer à l'ordinateur de plongée suivant.
- _Plein écran_  - Passer en mode plein écran.

=== Aide
- _À propos de Subsurface_  - Affiche un panneau avec le numéro de version de
  _Subsurface_ ainsi que les informations de licence.
- _Vérifier les mises à jour_  - Vérifier si une nouvelle version de
  Subsurface est disponible sur le http://subsurface-divelog.org/[site web de
  _Subsurface_ ].
- <<S_UserSurvey,_Sondge utilisateur_>> - Aidez à rendre _Subsurface_ encore
  meilleur en répondant à notre sondage utilisateur.
- _Manuel utilisateur_  - Ouvre une fenêtre affichant ce manuel utilisateur.


== Mobile Version

_Subsurface_ has a mobile version, which can be used to view the dives
stored in the user's cloud account.

=== How to use the mobile version
When you first open the mobile app, you will have to log into your cloud
account. To do this, click on the menu icon on the upper right, then click
on preferences. Enter your cloud email and password, then click on save.

To load dives the first time, click on the menu icon, and then click on
_Load Dives_. This will fetch the dive list from the cloud storage onto your
device. On subsequent runs, the divelist will be loaded automatically when
you open the app.

To view dive details, tap on any dive in the dive list. This will open the
dive details window, which shows the dive profile and below it, the dive
details. Any of the dive details can be changed.

To save changes made to the dive details, click on the back icon, then from
the menu select _Save Changes_. This will save your changes to the cloud
storage.


== ANNEXE A : informations spécifiques au système d'exploitation utilisé pour importer les informations de plongées depuis un ordinateur de plongée.

=== Assurez-vous que les pilotes (drivers) nécessaires sont installés
[icon="images/icons/drivers.jpg"]
[NOTE]
Le système d'exploitation de l'ordinateur nécessite les bons pilotes pour
communiquer avec l'ordinateur de plongée de la façon utilisée par
l'ordinateur de plongée (Bluetooth, USB, infra-rouge).

	* Sous Linux, les utilisateurs doivent avoir le bon module noyau de chargé. La
	  plupart des distributions Linux le font automatiquement, de telle sorte que
	  l'utilisateur n'ait rien à faire de particulier. Cependant, certains
	  protocoles de communication nécessitent des pilotes additionnels, plus
	  particulièrement pour certaines technologies telles que l'infra-rouge.

	* Sous Windows, le bon pilote devrait être téléchargé automatiquement la
	  première fois que l'utilisateur branche son ordinateur de plongée sur le
	  port USB de son ordinateur de bureau.

Sous Mac, les utilisateurs peuvent parfois avoir besoin d'installer
manuellement le bon pilote. Par exemple, pour le Mares Puck ou n'importe
quel autre ordinateur de plongée utilisant une interface USB-série basé sur
le composant Silicon Labs CP2101 ou similaire, le bon pilote est disponible
sous _Mac_OSX_VCP_Driver.zip_ sur le
http://www.silabs.com/support/pages/document-library.aspx?p=Interface&f=USB%20Bridges&pn=CP2101[dépôt
de documents et logiciels Silicon Labs].

[[S_HowFindDeviceName]]
=== Comment trouver le nom du périphérique branché sur USB et paramétrer les permissions en écriture
[icon="images/icons/usb.jpg"]
[NOTE]
Lorsqu'un utilisateur connecte un ordinateur de plongée en utilisant l'USB,
généralement _Subsurface_ proposera soit une liste déroulante contenant le
bon nom (ou le point de montage pour un Uemis Zurich) ou la liste sera
désactivée si aucun nom de périphérique n'est nécessaire. Dans les rares cas
où cela ne fonctionnerait pas, voici quelques suggestions pour trouver le
nom de votre périphérique ;

.Sur Windows :

Essayez simplement COM1, COM2, etc. La liste déroulante devrait contenir
tous les périphériques COM connectés.

.Sur MacOS :

La liste déroulante devrait contenir tous les ordinateurs de plongée
connectés.

.Sur Linux :

Il existe un moyen sûr de trouver le port :

 - Déconnecter le cable USB de l'ordinateur de plongée
 - Ouvrir un terminal
 - Taper la commande 'dmesg' et appuyer sur la touche Entrer
 - Connecter le cable USB de l'ordinateur de plongée
 - Taper la commande 'dmesg' et appuyer sur la touche Entrer

Un message similaire à celui-ci devrait apparaitre :

	usb 2-1.1: new full speed USB device number 14 using ehci_hcd
	usbcore: registered new interface driver usbserial
	USB Serial support registered for generic
	usbcore: registered new interface driver usbserial_generic
	usbserial: USB Serial Driver core
	USB Serial support registered for FTDI USB Serial Device
	ftdi_sio 2-1.1:1.0: FTDI USB Serial Device converter detected
	usb 2-1.1: Detected FT232BM
	usb 2-1.1: Number of endpoints 2
	usb 2-1.1: Endpoint 1 MaxPacketSize 64
	usb 2-1.1: Endpoint 2 MaxPacketSize 64
	usb 2-1.1: Setting MaxPacketSize 64
	usb 2-1.1: FTDI USB Serial Device converter now attached to ttyUSB3
	usbcore: registered new interface driver ftdi_sio
	ftdi_sio: v1.6.0:USB FTDI Serial Converters Driver

La troisième ligne en partant du bas montre que l'adaptateur FTDI USB est
détecté et connecté sur +ttyUSB3+. Cette information peut à présent être
utilisée pour les paramètres d'importation en tant que +/dev/ttyUSB3+ pour
que Subsurface utilise le bon port USB.

S'assurer que l'utilisateur possède les droits d'écriture sur le port série
USB :

Sur les systèmes similaires à Unix, les ports USB ne peuvent être accédés
que par des utilisateurs membres du groupe +dialout+. Si vous n'êtes pas
root, vous n'êtes peut-être pas membre de ce groupe et ne pouvez donc pas
utiliser le port USB. Si votre nom d'utilisateur est 'johnB' :

En tant que root, tapez : usermod -a -G dialout johnB+ (utilisateurs
d'Ubuntu : +sudo usermod -a -G dialout johnB+)  Cela ajoute johnB au groupe
+dialout+.
Tapez : +id johnB+     Cela liste tous les groupes auquel johnB appartient et
vérifiez que
l'appartenance au groupe est bien effectif. Le groupe +dialout+ devrait
être listé
parmi les différents IDs.
Sous certaines circonstances, les modifications ne prennent effet qu'après une déconnexionpuis reconnexion sur l'ordinateur (sous Ubuntu, par exemple).
Avec le bon nom de périphérique (par exemple +dev/ttyUSB3+) et avec un accès
en écriture au port USB, l'ordinateur de plongée devrait se connecter et
vous devriez pouvoir importer vos plongées.

[[S_HowFindBluetoothDeviceName]]
=== Setting up bluetooth enabled devices
[icon="images/icons/bluetooth.jpg"]
[NOTE]
For dive computers communicating through bluetooth like the Heinrichs
Weikamp Frog or the Shearwater Predator and Petrel there is a different
procedure to get the devices name to communicate with _Subsurface_. Follow
these steps:

 * *For the dive computer, after enabling Bluetooth, ensure it is in Upload mode.*

For Bluetooth pairing of the dive computer, refer to the manufacturer's user
guide. When using a Shearwater Predator/Petrel, select _Dive Log -> Upload
Log_ and wait for the _Wait PC_ message.

 * *Pair the _Subsurface_ computer with the dive computer.*

==== Sur Windows :

Bluetooth is most likely already enabled. For pairing with the dive computer
choose _Control Panel -> Bluetooth Devices -> Add Wireless Device_.  This
should bring up a dialog showing your dive computer (which should be in
Bluetooth mode) and allowing pairing. Right click on it and choose
_Properties-> COM Ports_ to identify the port used for your dive
computer. If there are several ports listed, use the one saying "Outgoing"
instead of "Incoming".

For downloading to _Subsurface_, the _Subsurface_ drop-down list should
contain this COM port already. If not, enter it manually.

Note: If there are issues afterwards when downloading from the dive computer
using other software, remove the existing pairing with the dive computer.

==== Sur MacOS :

Click on the Bluetooth symbol in the menu bar and select _Set up Bluetooth
Device..._. The dive computer should then show up in the list of
devices. Select it and go through the pairing process. This step should only
be needed once for initial setup.

Once the pairing is completed the correct device is shown in the 'Device or
Mount Point' drop-down in the _Subsurface_ *Import* dialog.

==== Sur Linux
Ensure Bluetooth is enabled on the _Subsurface_ computer.  On most common
distributions this should be true out of the box and pairing should be
straight forward. For instance, Gnome3 shows a Bluetooth icon on the right
of the toolbar at the top of the screen.  Users have reported difficulties
with some Bluetooth controllers.  If you have an onboard controller, try
that first.  It is simplest if you remove any USB Bluetooth dongles.  If you
have a USB dongle that came with your dive computer, try that before any
others.

Setting up a connection to download dives from your Bluetooth-enabled
device, such as the _Shearwater Petrel_, is not yet an automated process and
will generally require the command prompt.  It is essentially a three step
process.

 - Enable the Bluetooth controller and pair your dive computer</li>
 - Establish an RFCOMM connection
 - Download the dives with Subsurface

Ensure the dive computer is in upload mode. On the _Shearwater Petrel_ and
_Petrel 2_, cycle through the menu, select 'Dive Log', then 'Upload Log'.
The display will read 'Initializing', then 'Wait PC 3:00' and will
countdown.  Once the connection is established, the display reads 'Wait CMD
...' and the countdown continues. When downloading the dive from Subsurface,
the display reads 'Sending' then 'Sent Dive'.

To establish the connection, establish root access through +sudo+ or +su+.
The correct permission is required to download the dives in the computer. On
most Linux systems this means becoming a member of the dialout group (This
is identical as for many dive computers using a Linux USB port, descibed in
the previous section). On the command terminal, enter:

+sudo usermod -a -G dialout username+

Then log out and log in for the change to take effect.

===== Enabling the Bluetooth controller and pairing your dive computer

Attempt to set up the Bluetooth controller and pair your dive computer using
the graphical environment of the operating system. After setting the dive
computer to upload mode, click the Bluetooth icon in the system tray and
select 'Add new device'. The dive computer should appear. If asked for a
password, enter 0000.  Write down or copy the MAC address of your dive
computer - this needed later and should be in the form 	00:11:22:33:44:55.

If the graphical method didn't work, pair the device from the command
line. Open a terminal and use +hciconfig+ to check the Bluetooth controller
status

	$ hciconfig
	hci0:	Type: BR/EDR  Bus: USB
		BD Address: 01:23:45:67:89:AB  ACL MTU: 310:10  SCO MTU: 64:8
		*DOWN*
		RX bytes:504 acl:0 sco:0 events:22 errors:0
		TX bytes:92 acl:0 sco:0 commands:21 errors:0

This indicates a Bluetooth controller with MAC address 01:23:45:67:89:AB,
connected as hci0.  Its status is 'DOWN', i.e. not powered.  Additional
controllers will appear as hci1, etc.  If there is not a Bluetooth dongle
plugged in upon booting the computer, hci0 is probably the onboard.  Now
power on the controller and enable authentication:

	sudo hciconfig hci0 up auth+  (enter password when prompted)
	hciconfig
	hci0:  Type: BR/EDR  Bus: USB
		BD Address: 01:23:45:67:89:AB  ACL MTU: 310:10  SCO MTU: 64:8
		*UP RUNNING PSCAN AUTH*
		RX bytes:1026 acl:0 sco:0 events:47 errors:0
		TX bytes:449 acl:0 sco:0 commands:46 errors:0

+Check that the status now includes +'UP', 'RUNNING' AND 'AUTH'+.

If there are multiple controllers running, it's easiest to off the unused
controller(s). For example, for +hci1+:

	sudo hciconfig hci1 down

Next step is to 'trust' and 'pair' the dive computer. On distros with Bluez
5, such as Fedora 22, one can use a tool called +blutootctl+, which will
bring up its own command prompt.

	bluetoothctl
	[NEW] Controller 01:23:45:67:89:AB localhost.localdomain [default]
	[bluetooth]# agent on
	Agent registered
	[bluetooth]# default-agent
	Default agent request successful
	[bluetooth]# scan on                        <----now set your dive computer to upload mode
	Discovery started
	[CHG] Controller 01:23:45:67:89:AB Discovering: yes
	[NEW] Device 00:11:22:33:44:55 Petrel
	[bluetooth]# trust 00:11:22:33:44:55        <----you can use the tab key to autocomplete the MAC address
	[CHG] Device 00:11:22:33:44:55 Trusted: yes
	Changing 00:11:22:33:44:55 trust succeeded
	[bluetooth]# pair 00:11:22:33:44:55
	Attempting to pair with 00:11:22:33:44:55
	[CHG] Device 00:11:22:33:44:55 Connected: yes
	[CHG] Device 00:11:22:33:44:55 UUIDs: 00001101-0000-1000-8000-0089abc12345
	[CHG] Device 00:11:22:33:44:55 Paired: yes
	Pairing successful
	[CHG] Device 00:11:22:33:44:55 Connected: no

If asked for a password, enter 0000. It's ok if the last line says
'Connected: no'. The important part is the line above, +Pairing successful+.

If the system has Bluez version 4 (e.g. Ubuntu 12.04 through to 15.04),
there is probably not a +bluetoothctl+, but a script called
+bluez-simple-agent+ or just +simple-agent+.

	hcitool -i hci0 scanning
	Scanning ...
		00:11:22:33:44:55       Petrel
		bluez-simple-agent hci0 00:11:22:33:44:55

Once ther dive computer is pired, set up the RFCOMM connection

===== Establishing the RFCOMM connection

The command to establish an RFCOMM connection is:

+sudo rfcomm -i <controller> connect <dev> <bdaddr> [channel]+

- <controller>+ is the Bluetooth controller, +hci0+.
- <dev> is the RFCOMM device file, +rfcomm0+
- <bdaddr> is the dive computer's MAC address, +00:11:22:33:44:55+
- [channel] is the dive computer's Bluetooth channel we need to connect to.

If one omits it, channel 1 is assumed.  Based on a limited number of user
reports, the appropriate channel for the dive computer is probably:

- _Shearwater Petrel 2_: channel 5
- _Shearwater Petrel 1_: channel 1
- _Heinrichs-Weikamp OSTC Sport_: channel 1

E.g. to connect a _Shearwater Petrel 2_, set the dive computer to upload
mode and enter:

	sudo rfcomm -i hci0 connect rfcomm0 00:11:22:33:44:55 5 (enter a password, probably 0000, when prompted)

This gives the response:

	Connected /dev/rfcomm0 to 00:11:22:33:44:55 on channel 5
	Press CTRL-C for hangup

To connect a _Shearwater Petrel 1+ or + HW OSTC Sport+, set the dive
computer to upload mode and enter:

	sudo rfcomm -i hci0 connect rfcomm0 00:11:22:33:44:55   (enter a password, probably 0000, when prompted)
	Connected /dev/rfcomm0 to 00:11:22:33:44:55 on channel 1
	Press CTRL-C for hangup

If the specific channel the dive computer needs is not known, or the channel
in the list above doesn't work, the command +sdptool records+ should help
determine the appropriate channel. The output below is for a _Shearwater
Petrel 2_.

	sdptool -i hci0 records 00:11:22:33:44:55
	Service Name: Serial Port
	Service RecHandle: 0x10000
	Service Class ID List:
		"Serial Port" (0x1101)
		Protocol Descriptor List:
		"L2CAP" (0x0100)
		"RFCOMM" (0x0003)
		Channel: 5

For a Bluetooth dive computer not in the list above, or if the channel
listed is not correct, please let the Subsurface developers know on the user
forum or the developer mailing list _subsurface@subsurface-divelog.org_.

===== Download the dives with Subsurface</em>
After establishing the RFCOMM connection and while the dive computer's
upload mode countdown is still running, go to_Subsurface_, select
_Import->Import from dive computer_ and enter appropriate Vendor
(e.g. _Shearwater_), Dive Computer (_Petrel_), Device or Mount Point
(_/dev/rfcomm0_) and click _Download_.

[[_appendix_b_dive_computer_specific_information_for_importing_dive_information]]

== APPENDIX B: Dive Computer specific information for importing dive data.

[[S_ImportUemis]]
=== Importing from Uemis Zurich

[icon="images/icons/iumis.jpg"]
[NOTE]
_Subsurface_ downloads the information stored on the SDA (the built-in file
system of the Uemis) including information about dive spots and
equipment. Buddy information is not yet downloadable.  Things are very
similar to a normal USB-connected dive computer (the Uemis is one of those
that recharge when connected to the USB port).  The main difference is that
one does not enter a device name, but instead the location where the
UEMISSDA file system is mounted once connected to the dive computer. On
Windows this is a drive letter ( often 'E:' or 'F:'), on a Mac this is
'/Volumes/UEMISSDA' and on Linux systems this differs depending on the
distribution. On Fedora it usually is
'/var/run/media/<your_username>/UEMISSDA'. In all cases _Subsurface_ should
suggest the correct location in the drop down list.

After selecting the above device name, download the dives from the Uemis
Zurich. One technical issue with the Uemis Zurich download implementation
(this is a Uemis firmware limitation, not a _Subsurface_ issue) is that one
cannot download more than about 40-50 dives without running out of memory on
the SDA. This will usually only happen the very first time one downloads
dives from the Uemis Zurich.  Normally when downloading at the end of a day
or even after a dive trip, the capacity is sufficient. If _Subsurface_
displays an error that the dive computer ran out of space the solution is
straight forward.  Disconnect the SDA, turn it off and on again, and
reconnect it. You can now retry (or start a new download session) and the
download will continue where it stopped previously. One may have to do this
more than once, depending on how many dives are stored on the dive computer.

[[S_ImportingGalileo]]
=== Importing from Uwatec Galileo

[icon="images/icons/Galileo.jpg"]
[NOTE]
The Uwatec Galileo dive computers use infra red (IrDA) communication between
the dive computer and Subsurface. The Uwatec hardware uses a USB dongle
based on the serial infra-red (SIR) protocol and the MSC7780 IrDA controller
manufactured by MosChip and marketed by Scubapro and some electronics
companies.  Under Linux, the kernel already provides for communication using
the IrDA protocol. However, the user additionally needs to load a driver for
the IrDA interface with the dive computer. The easiest way is to load the
*irda-tools* package from the
http://irda.sourceforge.net/docs/startirda.html[Linux IrDA Project].  After
the installation of the irda-tools, the *root user* can specify a device
name from the console as follows: +irattach irda0+

After executing this command, Subsurface will recognise the Galileo dive
computer and download dive information.

Under Windows, a similar situation exists. Drivers for the MCS7780 are
available from some Internet web sites e.g.
http://www.drivers-download.com/Drv/MosChip/MCS7780/[www.drivers-download.com].
Windows-based IrDA drivers for the Uwatec can also be downloaded from the
ScubaPro web site, drivers being located on the download page for the
ScubaPro SmartTrak software.

For the Apple Mac, IrDA communication via the MCS7780 link is not available
for OSX 10.6 or higher.

[[S_ImportingDR5]]
=== Importing from Heinrichs Weikamp DR5

[icon="images/icons/HW_DR5.jpg"]
[NOTE]
When mounted as a USB drive the Heinrichs Weikamp DR5 saves a single UDDF
file for every dive.  Mark all the dives you'd like to import or open.
Note: The DR5 does not seem to store gradient factors nor deco information,
so for _Subsurface_ it is not possible to display them. Adjust the gradient
factors in the _Graph Settings_ in _Subsurface_ to generate a deco overlay
in the _Subsurface_ *Dive Profile* panel but please note that the deco
calculated by _Subsurface_ will most likely differ from the one displayed on
the DR5.


[[S_ImportingXDeep]]
=== Importing from xDEEP BLACK

[icon="images/icons/HW_xdeepblack.jpg"]
[NOTE]
Each dive has to be individually saved as UDDF file using "Export UDDF"
option in BLACK's logbook menu.  When mounted as a USB drive UDDF files are
available in LOGBOOK directory.  Note: The xDEEP BLACK saves NDL time but
does not seem to store gradient factors nor deco information, so for
_Subsurface_ it is not possible to display them. Adjust the gradient factors
in the _Graph Settings_ in _Subsurface_ to generate a deco overlay in the
_Subsurface_ *Dive Profile* panel but please note that the deco calculated
by _Subsurface_ will most likely differ from the one displayed on the xDEEP
BLACK.


=== Importing from Shearwater Predator using Bluetooth

[icon="images/icons/predator.jpg"]
[NOTE]
Using a Shearwater Predator one may be able to pair Bluetooth but then
encounter issues when downloading, showing errors like _Slip RX: unexp. SLIP
END_ on the Predator.  This might also arise when using other dive log
software and operating systems other than Linux. We have no detailed idea
about the source and how to fix this, but it is reported to be solved
sometimes by one of these steps:

 * use the Bluetooth dongle which came with the Shearwater Predator instead of
   the built-in one of the _Subsurface_ computer
 * switch to different Bluetooth drivers for the same hardware
 * switch off WiFi while using Bluetooth

[[S_PoseidonMkVI]]
=== Importing from Poseidon MkVI Discovery

[icon="images/MkVI.jpeg"]
[NOTE]
Download of dive logs from the MkVI is performed using a custom
communications adapter and the _Poseidon PC Configuration Software_,
obtained when purchasing the MKVI equipment. The latter is a Windows
application allowing configuration of equipment and storage of dive
logs. Communication between dive computer and desktop computer utilises the
IrDA infra-red protocol. Only data for one dive can be downloaded at a time,
comprising three files:

- Setup configuration for the dive and key dive parameters (file with a .txt
  extension)
- Dive log details (file with a .csv extension)
- Redbook format dive log (file with .cvsr extension). This is a compressed
  version of the dive log using a proprietary format.

_Subsurface_ accesses the .txt and the .csv files to obtain dive log
information.


=== Importing from APD Inspiration/Evolution CCR

[icon="images/APDComputer.jpg"]
[NOTE]
The dive logs of an APD Inspiration or similar CCR dive computer are
downloaded using a communications adapter and _AP Communicator_, obtained
when purchasing the equipment. The dive logs can be viewed using the _AP Log
Viewer_, within Windows or Mac/OS. However, APD logs can be viewed and
managed from within _Subsurface_ (together with dives using many other types
of dive computer). The APD inspiration dive logs are imported into
_Subsurface_ as follows:

- Download the dive using _AP Communicator_.
- Open a dive within the _AP Log Viewer_.
- Select the tab at the top of the screen, entitled "_Data_".
- With the raw dive log data show on the screen, click on "_Copy to
  Clipboard_".
- Open a text editor, e.g. Notepad (Windows) or TextWrangler (Mac).
- Copy the contents of the clipboard into the text editor and save the text
  file with a filename extension of _.apd_
- Within _Subsurface_, select _Import -> Import log files_ to open the
  xref:Unified_import[universal import dialogue].
- In the dropdown list towards the bottom right of the dialogue (labled
  'Filter:'), select "APD log viewer".
- On the list of file names select the _.apd_ file that has been created
  above. An import dialogue opens indicating the default settings for the data
  in the _.apd_ file. If any changes are required, do this as for
  xref:S_ImportingCSVDives[CSV imports].

image::images/APD_CSVimportF22.jpg["Figure: APD log viewer import", align="center"]

- The top left hand dropdown box in the import panel allows one to select the
  APD dive computer for which the dive log needs to be imported. The default
  it is DC1, _i.e._ the first of the two dive computers the APD uses. It is
  possible to sequentially import the data for both dive computers by first
  importing CD1 and then DC2.(*Hint*: The logs for the two dive computers are
  viewed by selecting _View -> Next DC_ from the Main Menu after the uploading
  has been completed)
- Click the _Ok_ button at the bottom of the import panel.

The APD dive log will appear within _Subsurface_. The dive
computer-generated ceiling generated by the Inspiration can be viewed by
selecting the appropriate button on the left of the *Dive Profile*. Cylinder
pressure data are not logged by the APD equipment but can be manually
entered in the _Equipment_ Tab.

== APPENDIX C: Exporting Dive log information from external dive log software.

The import of dive log data from external dive log software is mostly
performed using the dialogue found by selecting _Import_ from the Main Menu,
then clicking on _Import Log Files_. This is a single-step process, more
information about which can be found xref:Unified_import[here.] However, in
some cases, a two-step process may be required:

1. Export the foreign dive log data to format that is accessible from
  _Subsurface_.
2. Import the accessible dive log data into _Subsurface_.

This appendix provides some information about approaches to export dive log
data from foreign dive log software. The procedures below mostly apply to
Linux and/or Windows.

[[S_ImportingDivesSuunto]]
=== Exporting from *Suunto Divemanager (DM3, DM4 or DM5)*
[icon="images/icons/suuntologo.jpg"]
[NOTE]
DiveManager is a MS Windows application for Suunto dive computers.
Divemanager 3 (DM3) is an older version of the Suunto software. More recent
Suunto dive computers use Divemanager version 4 or 5 (DM4 or DM5). The
different versions of Divemanager use different methods and different file
naming conventions to export dive log data.

*Divemanager 3 (DM3):*

1. Start 'Suunto Divemanager 3' and log in with the name containing the logs
2. Do not start the import wizard to import dives from the dive computer.
3. In the navigation tree on the left side of the program-window, select the
   appropriate dives.
4. Within the list of dives, select the dives you would like to import later:
	* To select certain dives: hold 'ctrl' and click the dive
	* To select all dives: Select the first dive, hold down shift and select the
	  last dive
5. With the dives marked, use the program menu _File -> Export_
6. The export pop-up will show. Within this pop-up, there is one field called
   'Export Path'.
	* Click the browse button next to the field Export Path
		** A file-manager like window pops up
		** Navigate to the directory for storing the
   Divelog.SDE file
		** Optionally change the name of the file for saving
		** Click 'Save'
	* Back in the Export pop-up, press the button 'Export'
7. The dives are now exported to the file Divelog.SDE.

*Divemanager 4 (DM4) and Divemanager 5 (DM5):*

DM4 and DM5 use identical mechanisms for exporting dive logs.  To export a
divelog from Divemanager one needs to locate the DM4/DM5 database where the
dives are stored. the user can either look for the original database or make
a backup of the dives. Both methods are described here.

Locating the Suunto DM4 (or DM5) database:

1. Start Suunto DM4/DM5
2. Select 'Help -> About'
3. Click 'Copy' after text 'Copy log folder path to clipboard'
4. Now open Windows Explorer
5. Paste the address to the path box at the top of the File Explorer
6. The database is called DM4.db or DM5.db

Making a backup copy of the Suunto DM4/DM5 database:

1. Start Suunto DM4/DM5
2. Select 'File - Create backup'
3. From the file menu select the location and name for the backup, we'll use
   DM4 (or DM5) in here with the default extension .bak
4. Click 'Save'
5. The dives are now exported to the file DM4.bak (or DM5.bak)


=== Exporting from Atomic Logbook
[[Atomic_Export]]

[icon="images/icons/atomiclogo.jpg"]
[NOTE]
Atomic Logbook is a Windows software by Atomic Aquatics. It allows
downloading of dive information from Cobalt and Cobalt 2 dive computers.
The divelog is kept in a SQLite database at
C:\ProgramData\AtomicsAquatics\Cobalt-Logbook\Cobalt.db. This file can be
directly imported to Subsurface.


=== Exporting from Mares Dive Organiser V2.1
[[Mares_Export]]

[icon="images/icons/mareslogo.jpg"]
[NOTE]
Mares Dive Organiser is a Windows application. The dive log is kept as a
Microsoft SQL Compact Edition database with a '.sdf' filename extension. The
database includes all Dive Organiser-registered divers on the particular
computer and all Mares dive computers used. The safest way to obtain a copy
of the dive database is to export the information to another compatible
format which can be imported into _Subsurface_.

1. Within Dive Organiser, select _Database -> Backup_ from the main menu and
   back up the database to the desk top.  This creates a zipped file
   DiveOrganiserxxxxx.dbf.
2. Rename the file to DiveOrganiserxxxxx.zip. Inside the zipped directory is a
   file _DiveOrganiser.sdf_.
3. Extract the _.sdf_ file from the zipped folder to your Desktop.
4. The password for accessing the .zip file is _mares_.

[[S_ImportingDivingLog]]
=== Exporting from *DivingLog 5.0 and 6.0*

[icon="images/icons/divingloglogo.jpg"]
[NOTE]
The best way to bring your logs from DivingLog to Subsurface is to convert
the whole database. This is because other export formats do not include all
the details, and we would lack e.g. gas switches and information of what
units are used. With database import, all this information is included and
readily available for us.

To transfer all files from DivingLog to Subsurface, do the following:

1. In DivingLog open the 'File -> Export -> SQLite' menu
2. Select 'Settings' button
3. Set the 'RTF2Plaintext' to 'true'
4. Close the Settings dialog
5. Click 'Export' button and select the filename

Once this is done, open the saved database file with Subsurface and the
dives are automatically converted to our own format. Last step to do is save
the log file in Subsurface.

== ANNEXE D : Exporter un tableur vers le format CSV
[[S_Appendix_D]]

De nombreux plongeurs conservent un carnet de plongée sous forme de fichier
numérique, souvent un tableur avec différents champs et informations. Ces
données peuvent facilement être importées dans _Subsurface_ après que le
tableur a été converti en fichier CSV. Cette section explique la procedure
pour convertir un carnet de plongée enregistrée sous forme de tableur vers
un fichier CSV qui pourra ensuite être importé dans _Subsurface_. Créer un
fichier CSV est une tache simple malgré que la procédure soit différente
selon le tableur utilisé.

La première étape est d'organiser les données de plongées dans le tableur
pour que la première ligne contienne le nom (ou le titre) de chaque colonne
et que les informations de chaque plongée soient contenues sur une seule
ligne. _Subsurface_ supporte de nombreux éléments (Dive #, Date, Time,
Duration, Location, GPS, Max Depth, Mean Depth, Buddy, Notes, Weight et
Tags). L'utilisateur peut organiser les données de plongées selon quelques
règles simples :

1. Date : utiliser un des formats suivants : aaaa-mm-jj, jj.mm.aaaa, mm/jj/aaaa
2. Durée : le format est minutes:secondes.
3. Système d'unité : un seul système d'unité doit être utilisé (pas de mélange
   entre les unités impériales et métriques)
4. Étiquettes et équipiers : les valeurs doivent être séparées par des
   virgules.
5. Position GPS : vous devez utiliser les degrés décimaux, par exemple :
   30.22496 30.821798

=== _LibreOffice Calc_ et _OpenOffice Calc_

These are open source spreadsheet applications forming parts of larger open
source office suite applications. The user interaction with _LibreOffice_
and _OpenOffice_ is very similar.  In Libreoffice Calc the time format
should be set to minutes:seconds - [mm]:ss and dates should be set to one
of: yyyy-mm-dd, dd.mm.yyyy, mm/dd/yyyy. A typical dive log may look like
this:

image::images/LOffice_spreadsheetdata.jpg["FIGURE: Spreadsheet data", align="center"]

To export the data as a .CSV file from within LibreOffice click _File ->
Save As_. On the dialogue that comes up, select the _Text CSV (.csv)_ as the
file type and select the option _Edit filter settings_.

image::images/LOffice_save_as_options.jpg["FIGURE: Save as options", align="center"]

After selecting _Save_, select the appropriate field delimiter (choose _Tab_
to prevent conflicts with the comma when using this as a decimal point),
then select _OK_.

image::images/LOffice_field_options.jpg["FIGURE: Field options", align="center"]

One can double check the .CSV file by opening it with a text editor, and
then import the dive data as explained on the section
xref:S_ImportingCSVDives[Importing CSV dives].

=== Microsoft _Excel_

The field delimiter (called "_list separator_" in Microsoft manuals) is not
accessible from within _Excel_ and needs to be set through the _Microsoft
Control Panel_. After changing the separator character, all software on the
Windows machine use the new character as a separator.  One can change the
character back to the default character by following the same procedure,
outlined below.

- In Microsoft Windows, click the *Start* button, and then select _Control
  Panel_ from the list on the right-hand side.
- Open the _Regional and Language Options_ dialog box.
- Do one of the following: ** In Windows 7, click the _Formats_ tab, and then
  click _Customize this format_.  ** In Windows XP, click the _Regional
  Options_ tab, and then click _Customize_.
- Type a new separator in the _List separator_ box. To use a TAB-delimited
  file, type the word TAB in the box.
- Click _OK_ twice.

Below is an image of the _Control Panel_:

image::images/Win_SaveCSV2.jpg["FIGURE: Win List separator", align="center"]

To export the dive log in CSV format:

With the dive log opened in _Excel_, select the round Windows button at the
top left, then _Save As_.

image::images/Win_SaveCSV1.jpg["FIGURE: Excel save as option", align="center"]

Click on the left-hand part of the _Save as_ option, NOT on the arrow on the
right-hand. This brings up a dialogue for saving the spreadsheet in an
alternative format. From the dropdown list at the bottom of the dialogue,
marked _Save as Type:_, select _CSV(Comma delimited) (*.CSV)_. Ensure that
the appropriate folder has been selected to save the CSV file into.

image::images/Win_SaveCSV3.jpg["FIGURE: Excel save CSV dialogue", align="center"]

Select the _Save_ button. The CSV-formatted file is saved into the folder
that was selected. One can double check the .CSV file by opening it with a
text editor, and then import the dive data as explained on the section
xref:S_ImportingCSVDives[Importing CSV dives].

[[S_APPENDIX_E]]
== ANNEXE E : Créer un modèle d'impression personnalisé

_Subsurface_ provides a mechanism to create or modify templates for printing
dive logs in order to produce customised printouts of dive logs. Templates,
written in HTML as well as a simple Grantlee instruction set, are rendered
to the print device by _Subsurface_.

Templates are accessed using the print dialogue (see image *B* below).

image::images/Print1_f22.jpg["FIGURE: Print dialogue", align="center"]

The buttons under the _Template_ dropdown box allows one to _Edit_,
_Delete_, _Import_ and to _Export_ templates (see image *A* above). New or
modified templates are stored as HTML files in the same directory as the
dive log being processed. In order to create or modify a template, select
the _Custom_ template from the template dropdown list in the print dialogue
(see image *B* above), then select _Edit_.

The Edit Panel comprises three tabs:

image::images/Template1_f22.jpg["FIGURE: template edit dialogue", align="center"]

1) The _Style_ tab (image *A* above) controls the font, line spacing and colour
   template used for printing the dive log.  The style attributes are
   editable. Choose one of the four colour palets used for colour printing.

2) The _Colors_ tab (image *B* above) allows editing the colours used for
   printing the dive log. The colours are highly customisable: the _Edit_
   buttons in the _Colors_ tab allows choosing abritrary colours for different
   components of the dive log printout.

3) The _Template_ tab of the Edit Panel (see image below) allows creating a
   template using HTML as well as a few Grantlee programming
   primitives. Grantlee provides the ability to create and format HTML code in
   a highly simple but efficient way (see below). The HTML of the template can
   be edited and saved. The saved template is stored in the same directory as
   the dive being processed. By default, a _Custom_ template is a skeleton with
   no specific print instructions. The informastion being printed needs to be
   specified and formatted in the by replacing the section marked with: "<!--
   Template must be filled -->". Writing HTML code with Grantlee instructions
   allows unlimited freedom in determining what is printed an in which way it
   should be rendered.

image::images/Template2_f22.jpg["FIGURE:Template tab", align="center"]

One can adapt any of the existing templates and save it to the dive log
directory. The standard templates (e.g. One dive, Six dives, Table) can be
modified in this way.

To write a custom template the following elements must exist so that the
template will be correctly handled and rendered.

=== Main dive loop
_Subsurface_ exports a dive list called (*dives*) to the _Grantlee_
backend. It is possible to iterate over the list as follows:

.template.html
....
	{% for dive in dives %}
		<h1> {{ dive.number }} </h1>
	{% endfor %}
....

.output.html
....
	<h1> 1 </h1>
	<h1> 2 </h1>
	<h1> 3 </h1>
....

Additional information about _Grantlee_ can be found
http://www.grantlee.org/apidox/for_themers.html[here]

=== Grantlee exported variables
Only a subset of the dive data is exported:
|====================
|*Name*|*Description*
|number| (*int*) dive number
|id| (*int*) unique dive ID, should be used to fetch the dive profile
|date| (*string*) data of the dive
|time| (*string*) time of the dive
|location| (*string*) location of the dive
|duration| (*string*) duration of the dive
|depth| (*string*) depth of the dive
|divemaster| (*string*) divemaster data
|buddy| (*string*) buddy data
|airTemp| (*string*) air temperature of dive
|waterTemp| (*string*) water temperature of dive
|notes| (*string*) dive notes
|rating| (*int*) dive rating ranges from 0 to 5
|sac| (*string*) sac value
|tags| (*string*) all dive tags concatenate together
|gas| (*string*) used gas cylinder
|=====================

_Subsurface_ also exports *template_options* data. This data must be used as
_CSS_ values to provide a dynamically editable template. The exported data
is shown in the following table:
|====================
|*Name*|*Description*
|font| (*string*) font family
|borderwidth| (*int*) border-width value dynamically calculated as 0.1% of the page width with minimum value of 1px
|font_size| (*double*) size of fonts in vw, ranges between 1.0 and 2.0
|line_spacing| (*double*) distance between text lines, ranges between 1.0 and 3.0
|color1| (*string*) background color
|color2| (*string*) primary table cell color
|color3| (*string*) secondary table cell color
|color4| (*string*) primary text color
|color5| (*string*) secondary text color
|color6| (*string*) border colors
|=====================

.template.html
....
	border-width: {{ template_options.borderwidth }}px;
....

.output.html
....
	border-width: 3px;
....

Another variable that _Subsurface_ exports is *print_options*. This variable
contains a single member:
|=====================
|*Name*|*Description*
|grayscale | Use _CSS_ filters to convert the page into grayscale (should be added to body style to enable printing grayscale prints)
|=====================


.template.html
....
	body {
		{{ print_options.grayscale }};
	}
....

.output.html
....
	body {
		-webkit-filter: grayscale(100%);
	}
....

=== Defined CSS selectors

As the dive profile is placed after rendering, _Subsurface_ uses a special
_CSS_ selectors to do some searches in the HTML output. The _CSS_ selectors
in the following table should be added.

|====================
|*Selector*|*Type*|*Description*
|dive_{{ dive.id }} | id | is used to fetch the relevant dive profile
|diveProfile | class | each div that will contain a dive profile should have this class selector in addition to the dive_{{ dive.id }} id selector
|dontbreak | class | prevents the div with this class to be divided into two pages, this can be used
in flow layout templates only (when data-numberofdives = 0)
|=====================

IMPORTANT: Rendering dive profiles is not supported for flow layout templates (when
data-numberofdives = 0).

=== Special attributes

There are two ways of rendering- either rendering a specific number of dives
in each page or make _Subsurface_ try to fit as much dives as possible into
one page (_flow_ rendering).

The *data-numberofdives* data attribute is added to the body tag to set the
rendering mode

- render 6 dives per page:

....
	<body data-numberofdives = 6>
....

- render as much dives as possible:

....
	<body data-numberofdives = 0>
....

IMPORTANT: All CSS units should be in relative lengths only, to support printing on any
page size.

== APPENDIX F: FAQs.
[[S_APPENDIX_F]]
=== Subsurface appears to miscalculate gas consumption and SAC
[[SAC_CALCULATION]]
'Question': I dived with a 12.2 l tank, starting with 220 bar and ending
with 100 bar, and I calculate a different SAC compared what _Subsurface_
calculates. Is _Subsurface_ miscalculating?

'Answer': Not really. What happens is that _Subsurface_ actually calculates
gas consumption differently - and better - than you expect.  In particular,
it takes the incompressibility of the gas into account.  Traditionally, Gas
consumption and SAC should be: +consumption = tank size x (start pressure -
end pressure)+

and that's true for an ideal gas, and it's what you get taught in dive
theory.  But an "ideal gas" doesn't actually exist, and real gases actually
don't compress linearly with pressure. Also, you are missing the fact that
one atmosphere of pressure isn't actually one bar.  So the *real*
calculation is:

+consumption = (amount_of_air_at_beginning - amount_of_air_at_end)+

where the amount of air is *not* just "tank size times pressure in bar".
It's a combination of: "take compressibility into account" (which is a
fairly small issue under 220 bar - you'll see more differences when you do
high-pressure tanks with 300bar) and "convert bar to atm" (which is the
majority of your discrepancy).  Remember: one ATM is ~1.013 bar, so without
the compressibility, your gas use is:

+12.2*((220-100)/1.013)+

which is about 1445, not 1464. So there was 19 l too much in your simple
calculation that ignored the difference between 1 bar and one ATM.  The
compressibility does show up above 200 bar, and takes that 1445 down about
eight litres more, so you really did use only about 1437 l of air at surface
pressure.

So be happy: your SAC really is better than your calculations indicated.  Or
be sad: your cylinder contains less air than you thought it did.  And as
mentioned, the "contains less air than you thought it did" really starts
becoming much more noticeable at high pressure. A 400 bar really does not
contain twice as much air as a 200 bar one. At lower pressures, air acts
pretty much like an ideal gas.

=== Some dive profiles have time discrepancies with the recorded samples from my dive computer...

_Subsurface_ ends up ignoring surface time for many things (average depth,
divetime, SAC, etc).  'Question': Why do dive durations in my dive computer
differ from that given by _Subsurface_?

'Answer': For example, if you end up doing a weight check (deep enough to
trigger the "dive started")  but then come back up and wait five minutes for
your buddies, your dive computer may say that your dive is 50 minutes long -
because you have fifty minutes worth of samples - but subsurface will say
it's 45 minutes - because you were actually diving for 45 minutes.  It's
even more noticeable if you do things like divemastering the initial OW
dives, when you may stay in the water for a long time, but spend most of it
at the surface. And then you don't want that to count as some kind of long
dive”.

=== Some dive profiles are missing from the download

[[DC_HISTORY]]
'Question': I cannot download all my dives, only the most recent ones even
though my dive computer's manual states that it records history of e.g. 999
dives.

'Answer': Dive history is different than the dive profiles on the log.  The
history only keeps track of the total number of dives and total amount of
time spent below surface. The logs, on the other hand, store the dive
profile, but they have limited amount of memory to do so. The exact amount
of dive profiles that can be stored on the device depend on sample interval
and duration of the dives. Once the memory is full the oldest dives get
overwritten with new dives. Thus we are only able to download the last 13,
30 or 199 dives.

If you have downloaded your dives to different dive logging software before
they were overwritten, there is a high change that Subsurface can import
these. However, if the logs are only on your dive computer, they cannot be
salvaged after being over written by new dives.