// :author: Manual authors: Jacco van Koll, Dirk Hohndel, Reinout Hoornweg, Linus Torvalds, Miika Turkia, Amit Chaudhuri, Jan Schubert, Willem Ferguson, Salvador Cuñat
*Manual authors*: Jacco van Koll, Dirk Hohndel, Reinout Hoornweg, Linus Torvalds, Miika Turkia, Amit Chaudhuri, Jan Schubert, Willem Ferguson, Salvador Cuñat
Welcome as a user of _Subsurface_, an advanced dive logging programme with extensive infrastructure to describe, organise and interpret scuba and free dives. _Subsurface_ binaries are available for Windows PCs (Win XP or later), Intel based Macs (OS/X) and many Linux distributions. _Subsurface_ can be built for many more hardware platforms and software environments where Qt and libdivecomputer are available.
The scope of this document is the use of the _Subsurface_ program. To install the software, consult the _Downloads_ page on the http://subsurface.hohndel.org/[_Subsurface_ web site]. Please discuss issues with this program by sending an email to mailto:subsurface@hohndel.org[our mailing list] and report bugs at http://trac.hohndel.org[our bugtracker]. For instructions on how to build the software and (if needed) its dependencies please consult the INSTALL file included with the source code.
The _Subsurface_ window is usually divided into four panels and has a *Main Menu* (File Import Log View Filter Help) at the top of the window (for Windows and Linux) or the top of the screen (for Mac and Ubuntu Unity). The screen shots in this manual were taken on a Ubuntu system, so they don't show the main menu as part of the _Subsurface_ window. The four panels are
1) The *Dive List* to the bottom left containing a list of all the dives in your dive log. You can select and highlight a dive on the dive list by clicking on it. In most situations you can also use the cursor up/down keys to switch between dives.
3) The *Dive Info* to the top left, giving more detailed information on the selected dive, including some statistics for the selected dive or for all highlighted dive(s).
You can drag the dividers between panels in order to change the size of any of the panels. _Subsurface_ remembers the position of the dividers, so the next time _Subsurface_ starts it uses the positions of the dividers when the program was executed previously.
If one dive is selected, the dive location, detailed information and profile of the _selected dive_ are shown in the respective panels. On the other hand, if one highlights more than one dive the last highlighted dive is the _selected dive_, but summary data of all _highlighted dives_ is shown in the *Stats* tab of the *Dive Info* panel.
You can determine which of the four panels you wish to see by selecting the *View* option on the main menu and which gives the user several choices of display:
Like many other functions that can be accessed via the Main Menu, these options can be triggered using keyboard shortcuts as well. The shortcuts for your system are shown with an underline in the menu entries. Since different Operating Systems and your chosen language may cause _Subsurface_ to use different shortcut keys we won't try to list them here in the user manual.
When you start the program for the first time, it shows no information at all. This is because the program doesn't have any dive information available. In the following sections we will describe how to create a new logbook.
Select _File -> New Logbook_ from the main menu. All existing dive data are cleared so that new information can be added. If there is unsaved data in an open logbook, _Subsurface_ will ask you if you want to save the open logbook before a new logbook is created.
2. Import dive information directly from a dive computer if it is supported by _Subsurface_. The latest list of dive computers supported by _Subsurface_ can be found at: link:http://subsurface.hohndel.org/documentation/supported-dive-computers/[Supported dive computers].
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 written 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 your 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 (*Dive Notes* and *Equipment*), as well as the *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. We will now consider each of the tabs used for data entry.
This panel contains the date, time and place information for a particular dive, environmental conditions, co-divers and buddies, as well as some descriptive information. The message in a blue box at the top of the panel indicates that you are in the process of adding information about your dive. If you click on the *Dive Notes* tab, the following fields are visible:
The *Starttime* field reflects the date and the time of the dive. By clicking the down-arrow on the right of that field you can display a calendar from which you can choose the correct date. The hour and minutes values can also be edited by clicking on each of them in the text box and by overtyping the information displayed.
*Air and water temperatures*: Type in the air and water temperatures during the dive into these fields to the right of the Starttime. You do not need to type in units of temperature: Subsurface supplies these automatically, you only need type the number. (The units selected in the 'Preferences' [red]#[[URL link]]# will determine whether metric or imperial units are displayed)
*Location*: Here you enter the name of the dive site, e.g. "Tihany, Lake Balaton, Hungary". Auto completion of location names will make this easier when you frequently dive at the same sites.
*Coordinates*: The geographic coordinates of the dive site should be entered here. These can come from three sources:
a. You can enter the coordinates by hand if you happen to know what they are. You need to enter them as decimal degrees, e.g: N30° 13.49760' , E30° 49.30788'.
b. You can find the coordinates on the world map in the bottom right hand part of the Subsurface window. The map displays a green bar indicating "No location data - move the map and double-click to set the location". Upon a double-click at the appropriate place, the green bar disappears and the coordinates are stored.
c. You can obtain the coordinates from the _Subsurface_ Companion app if you have an Android device with GPS and you stored the coordinates of the dive site using that device.
*Divemaster*: Enter the name of the dive master or dive guide for this dive. Again, this field offers auto completion based on the list of dive masters in the current logbook.
*Buddy*: Enter the name(s) of the buddy / buddies who accompanied you on the dive. Auto completion based on the list of buddies in the current logbook is offered.
*Tags*: You may enter tags here (separate them by commas) that describe the type of dive you performed. Examples of common tags are boat, drift, training, cave, etc. _Subsurface_ has many built-in tags. Auto completion is once again offered. For instance, if you typed +cav+, then the tags *cave* and *cavern* are shown for the user to choose from.
The *Save* and *Cancel* 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. Here is an example of a completed Dive Notes panel:
The Equipment tab allows the user to enter information about the type of cylinder and gas used, as well as the weights used for a dive. The message in a blue box at the top of the panel:
indicates that you are in the process of adding equipment information for the dive. 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).
The + button at the top right allows you to add more cylinders for this dive. The dark dustbin icon on the left allows you to delete information for a cylinder.
Start by selecting a cylinder type. The AL80 cylinder is shown as the default cylinder type (you can change this default in the preferences if you usually dive with a different type of tank). If you wish to change the tank used on this dive, click on the AL80. This will bring up a dropdown list, accessible through a down-arrow:
Use the drop-down list to select the cylinder type you used for this dive. The *Size* of the cylinder as well as its working pressure (*WorkPress*) will automatically be shown in the dialogue.
Now you need to indicate the starting pressure and the ending pressure of the gas used during your dive. The unit of pressure (metric/imperial) corresponds to the setting you chose in the preferences [red]#[[LINK]]#.
Finally you need to type in the gas mixture that you used. If you used air, you can enter 21% or leave the field blank. If you used nitrox or trimix, specify the percentage of oxygen and the percentage of helium. Leave any inappropriate fields empty. Add information for any additional cylinders by using the + button at the top right hand. Here is an example of a complete description for a dive using two cylinders (air and EAN40):
*Weights*: Information about the weight system used during a dive can be entered using a dialogue very similar to that of the cylinder information. If you click the + button on the top right of the weights dialogue, the table looks like this:
Use the drop-down list to select your type of weight system. In the *Weight* field, type in the weight used during the dive. 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 and a weight belt:
The *Dive Profile* (a graphical representation of the depth of your dive as a function of time) is indicated in the panel on the top right hand of the _Subsurface_ window. When you manually add a dive to your logbook, _Subsurface_ presents a default dive profile that you need to modify to best represent the dive being described:
_Modifying the dive profile_: When you move the cursor around the dive profile, its position is indicated by two red lines as shown below. The depth and time that the cursor represents are indicated, respectively on the left hand and bottom axes. The units (metric/imperial) on the axes are determined by the *preference* settings [red]#[[LINK]]#. The dive profile itself comprises several line segments demarcated by waypoints (white dots on the profile, as shown above). The default dive depth is 15m.
If your dive depth was 21m then you need to drag the appropriate waypoints downwards to represent 21m. To add a waypoint, double-click on any line segment. To remove a waypoint, right-click on it and choose "Remove this point" from the context menu. You will also need to drag the waypoints to represent an accurate time duration for your dive. Below is a dive profile that represents a dive to 21m for 31 min., followed by a 3 minute safety stop at 5m.
_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 illustrated above. The gas mixtures of segments of the dive profile can be edited. This is done by clicking on the gas description for a particular waypoint and selecting the appropriate choice 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:
Below is the profile of a dive to 21m for 31 min. with a switch from air to EAN40 on the ascent. In this case the first cylinder in the *Equipment* tab contained air and the second cylinder contained EAN40.
The information entered in the *Dive Notes* tab, the *Equipment* tab as well as the *Dive Profile* can now be saved in your logbook by using the two buttons on the top right hand of the Dive Notes tab. If you click _Save_, the dive data are saved in the current logbook. If you click _Cancel_, the newly entered dive data are discarded. When you exit _Subsurface_ it will prompt you to save the logbook with the new dive(s) on your computer.
The use of dive computers allows collecting a large amount of information about each dive, e.g. a detailed record of depth, durations, rates of ascent/descent and of gas partial pressures. _Subsurface_ can capture this information and present it to you as part of the dive information. _Subsurface_ can obtain dive information from a wide range of dive computers. The latest list of supported dive computers can be found at: link:http://subsurface.hohndel.org/documentation/supported-dive-computers/[Supported dive computers].
To import dive information from a dive computer to your computer with _Subsurface_, it is necessary that the two pieces of equipment must communicate. 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, you need to find the appropriate information to instruct _Subsurface_ where and how to import the dive information. *Appendix A* provides the technical information to help you achieve this for different operating systems and *Appendix B* has dive computer specific information.
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 _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 your dive computer (at least for those not charging while connected via USB). If, for some reason, you wish to import ALL dives from the dive computer, even though some may already be in the logbook, you can tick the box labeled _Force download of all dives_.
- The dialogue has two drop-down lists, *Vendor* and *Dive Computer*. On the *vendor* drop-down list select the make of your computer, e.g. Suunto, Oceanic, Uwatec, Mares. On the *Dive Computer* drop-down list, select the model name of your dive computer, 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 your dive computer. Select the appropriate port name. Consult *Appendix A* and *Appendix B* for technical details to find the appropriate port information for your dive computer and, in some cases, how to do the correct settings to the operating system of your _Subsurface_ computer.
- If there is a problem in communicating with your dive computer, an error message will be shown, similar to this text: "Unable to open /dev/ttyUSB0 Mares (Puck Pro)". In this case, consult *Appendix A* for information specific to the operating system of your _Subsurface_ computer and consult *Appendix B* for information specific to some dive computers.
4) Consult *Appendix A* and make sure you specified the correct Mount Point (see above). If your _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 your _Subsurface_ computer is missing required drivers to interact with the download cable and connected dive computer.
could take some time. Please be patient. The _Download_ dialogue shows a progress bar at the bottom of the dialogue (but for some dive computers the progress information could be inaccurate as we cannot determine until after all data was downloaded how much downloadable data there is):
When download of the dive information is complete, 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.
The information from your dive computer is not complete and you need to add more details in order to have a more complete record of your dives. To do this, use the *Dive Notes* and the *Equipment* tabs on the top left hand of the _Subsurface_ window.
The date and time of the dive, gas mixture and perhaps water temperature is shown as obtained from the dive computer, but you need to add some information by hand in order for a more complete dive record. The message in a blue box at the top of the panel indicates that you are in the process of adding information about a dive. If you click on the *Dive Notes* tab, the following fields are visible:
The *Starttime* field reflects the date and the time of the dive, as supplied by the dive computer. It should therefore not be necessary to edit this, but you could make changes by clicking the down-arrow on the right of that field to display a calendar from which you can choose the correct date. The hour and minutes values can also be edited 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 these fields to the right of the Starttime. Many dive computers supply water temperature information and this field may therefore not require editing. If editing is required, you do not need to type in units of temperature: Subsurface supplies these automatically, only a number is required. (The units selected in the 'Preferences' [red]#[[URL link]]# will determine whether metric or imperial units are displayed)
*Location*: Here type in text that describes the site where you did this dive, e.g. "Tihany, Lake Balaton, Hungary". Auto completion of location names will make this easier when you frequently dive at the same sites.
a. You can enter the coordinates by hand if you happen to know what they are. You need to enter them as decimal degrees, e.g: N30° 13.49760', E30° 49.30788'.
b. You can find the coordinates on the world map in the bottom right hand part of the Subsurface window. The map displays a green bar indicating "No location data - move the map and double-click to set the location". Upon a double-click at the appropriate place, the green bar disappears and the coordinates are stored.
c. You can obtain the coordinates from the _Subsurface_ Companion app if you have an Android device with GPS and you stored the coordinates of the dive site using that device.
*Divemaster*: Enter the name of the dive master or dive guide for this dive. Again, this field offers auto completion based on the list of dive masters in the current logbook.
*Buddy*: Enter the name(s) of the buddy / buddies who accompanied you on the dive. Auto completion based on the list of buddies in the current logbook is offered.
*Tags*: You may enter tags here (separate them by commas) that describe the type of dive you performed. Examples of common tags are boat, drift, training, cave. _Subsurface_ has many built-in tags. If you start to type a tag, the program will list the tags that correspond to your typing. For instance, if you typed +cav+, then the tags *cave* and *cavern* are shown for the user to choose from.
The *Save* and *Cancel* 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. Here is an example of a completed Dive Notes panel:
The Equipment tab allows the user to enter information about the type of cylinder and gas you used, as well as the weights used for that dive. The message in a blue box at the top of the panel:
indicates that you are in the process of adding equipment information for the dive. 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).
In most cases _Subsurface_ obtains the gas used from the dive computer and automatically inserts the gas composition(% oxygen) in the table. The + button at the top right allows you to add more cylinders for this dive. The dark dustbin icon on the left allows you to delete information for a cylinder.
Start by selecting a cylinder type. The AL80 cylinder is shown as the default cylinder type (you can change this default in the preferences if you usually dive with a different type of tank). If you wish to change the tank used on this dive, click on the AL80. This will bring up a drop-down list, accessible through a down-arrow:
Use the drop-down list to select the cylinder type you used for this dive. The *Size* of the cylinder as well as its working pressure (*WorkPress*) will automatically be shown in the dialogue.
Now you need to indicate the starting pressure and the ending pressure of the specified gas during your dive. The unit of pressure (metric/imperial) corresponds to the setting you chose in the preferences [red]#[[LINK]]#.
Finally you need to type in the gas mixture that you used. If you used air, you can enter 21% or leave the field blank. If you used nitrox or trimix, specify the percentage of oxygen and the percentage of helium. Leave any inappropriate fields empty. Add information for any additional cylinders by using the + button at the top right hand. Here is an example of a complete description for a dive using two cylinders (air and EAN40):
*Weights*: Information about the weight system used during a dive can be entered using a dialogue very similar to that of the cylinder information. If you click the + button on the top right of the weights dialogue, the table looks like this:
Use the drop-down list to select your type of weight system. In the *Weight* field, type in the weight used during the dive. 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 and a weight belt:
The information entered in the *Dive Notes* tab, the *Equipment* tab can be saved with all the other information of your dives in your logbook by using the two buttons on the top right hand of the *Dive Notes* tab. If you click _Save_, the dive data are saved. If you click _Cancel_, the newly entered dive data are deleted, although the dive profile obtained from the dive computer will be retained. When you exit _Subsurface_ there is a final prompt to confirm that the new data should be saved.
_Subsurface_, because you can probably import your divelog. _Subsurface_ will import divelogs from a range of other dive log software. Some software is supported natively (e.g. divelogs.de, JDiveLog, MacDive, and Suunto DM4), for others you have to export your logbook to XML and then _Subsurface_ can import that XML file (Suunto DM3, DivingLog). _Subsurface_ can also import UDDF and UDCF files that are used by some divelog software and even some divecomputers like the Heinrichs & Weikamp DR5. Finally, for some divelog software we currently suggest to import your logbook 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.
Mares Dive Organiser is a Windows application. The dive log is kept as a Microsoft SQL Compact Edition data base with a .SDF filename extension. The data base includes all Dive Organiser-registered divers on the particular computer and all Mares dive computers used. The safest way to obtain a copy of this data base is, within Dive Organiser, to select Database -> Backup from the main menu and to back up the data base to your desk top. This creates a zipped file DiveOrganiserxxxxx.dbf. Rename the file to DiveOrganiserxxxxx.zip. Inside the zipped directory is a file _DiveOrganiser.sdf_. Extract it from the zipped folder to your Desktop.
Then use _www.divelogs.de_ as a mechanism to extract the dive information from the file. Create a user account in divelogs.de , log into that web site, then select Import Logbook -> Dive Organiser from the menu on the left hand side. Follow the instructions carefully to transfer the dive information from the Dive Organiser data base to divelogs.de.
The import of dive information from _divelogs.de_ is simple, using a single dialogue box. Select _Import->Import form Divelogs.de_ from the Main Menu. This brings up a dialogue box (see figure on left [A] below). You need to enter a user-ID and password for _divelogs.de_ into the appropriate fields. Then select the _Download_ button. Download from _divelogs.de_ starts immediately, evident on a progress bar in the dialogue box. At the and of the download, the successful status is indicated (see figure on the right [B], below). Select the _Apply_ button. The imported dives appear in the *Dive List* panel.
Some attributes in your file may not get processed properly. Select _Import->Import Files_ from the Main Menu. Then select the UDDF file to be imported.
If you have an Android device with GPS, you can obtain the coordinates of the place where you are diving and automatically pass them to your Subsurface divelog. To do this you need to:
- Register on the http://api.hohndel.org/login/[Subsurface companion web page]. You will receive a confirmation mail with instructions and a personal *DIVERID*, a long number that gives access to the 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 your smartphone
On first use the app has three options:
* _Create a new account._ Equivalent to registering in Subsurface companion page.
* _Retrieve an account._ If you forgot your DIVERID you will receive an email to recover the number.
* _Use an existing account._ You are prompted for your DIVERID. The app saves your DIVERID and does not ask for it again unless you use the _Disconnect_ menu option (see below).
Now you're 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 dive.
Touching the "+" icon on the top right to add a new dive site. You will be prompted for a place name (or asked to activate the GPS if it was turned off). The main screen shows a list of dive locations, each with place name, date and time. Some dives may have an arrow-up icon on the selection box to the left (see image B in the middle, below) indicating that they require upload to the server.
The new dive points are now stored on the server and can be downloaded to the _Subsurface_ dive log whenever you upload or add your dive to _Subsurface_. After a dive trip using the Companion app, all dive locations are ready to be saved on your Subsurface dive log (see below).
- _User ID._ Obtained by registering as indicated above. The easiest way to introduce it is simply to copy and paste from the confirmation mail but, off course, you can type it each character at a time.
_How does the background service work?_ Let's assume we've set 5 minutes and 50 meters in the settings above, the app will fix a location, then another one each 5 minutes. If this 2nd (3rd, 4th ...) location is within a radius of 50 meters from the previous one, it is not saved. After another 5 minutes there will be a new try, and so on. This way, if we are in a static position, we'll only get one location fix, but if we travel we can have a trace of our journey.
This is a badly named option. It disconnects your app from the server by resetting your ID in the app, showing the first screen where you can create an account, retrieve the ID for an existing one or use your own ID. Disconnecting is useful if you download the dive positions of another registered diver using the your Android device.
You have to download dive(s) from a dive computer or enter dives 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 will be blank. Provide the DIVERID. Then select the _Download_ button and the download begins. When this is completed you see the screen on the right (B), below:
Note that the _Apply_ button is now active. Click on it to update the locations of the newly entered or uploaded dives in _Subsurface_ which applies the coordinates and names you gave them for all the new dives that match the date-times of the uploaded GPS localities.
_Features, issues and tips._ Since _Subsurface_ matches GPS locations from the Android device and dive information from your dive computer based on date-time data, automatic assignment of GPS data to dives is dependent on agreement of date and time between these two devices. If there is a large difference between the time in your dive computer and the time in your Android device, _Subsurface_ is unable to identify the dive that matches a location and nothing happens. Similar date-times may be not always be possible. A dirty hack is manually editing the date-time of a dive in Subsurface's Dive List _before_ downloading the GPS data and then to edit the date-time back again _after_ downloading GPS data.
The Dive 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 oxygen toxicity units (OTU) incurred.
The Stats tab gives summary statistics for more than one dive, assuming that more than one dive have been selected in the *Dive List*. Highlight more than one dive by 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, dive depth, water temperature and surface air consumption (SAC).
Of all the panels in _Subsurface_, the Dive Profile contains the most detailed information about each dive. 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 rate compared to the recommended speed of going up or down in the water column. This information is given using different colours:
The profile also includes depth readings for the peaks and troughs in the graph. Thus you should see the depth of the deepest point and other peaks. Mean depth is marked with a horizontal red line.
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 tank pressure gives you information about the momentary SAC rate (Surface Air Consumption – often also called RMV – Respiratory Minute Volume) when using an air integrated dive computer. Here the colour coding is not relative to some absolute values but relative to the average normalized 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. The colour coding is obviously only possible when a tank sensor is connected and tank pressure readings during the dive are available.
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.
Measurements of *depth differences* can be achieved by using the button with two vertical bars at the right of the dive profile panel (see above figure, bottom right). Drag the red dots to the two points on the dive profile which you would like to measure. Information is given along the line connecting the two red dots.
The dive profile can include further information that is typically more interesting for tec divers. Enabling these is described in the section entitled Setting up Preferences. Basically you can include graphs of the *partial pressures* of O2, N2, and He during the dive as well as a calculated and dive computer reported deco ceilings (only visible for deep, long, or repetitive dives). The partial pressure graphs are added below the profile data, the calculated ceiling is shown as a green overlay on top of the dive profile. Above the profile the currently used gradient factors are shown (e.g. GF 35/75). Please note that these are NOT the gradient factors in use by the dive computer in question, but the gradient factors used by _Subsurface_ to calculate deco obligations during the dive.
The graph can also include the dive computer reported *ceiling* (or more precisely, the first deco stop that the dive computer recorded – note that 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). Because of the differences in used algorithms and amount of data available (and factors taken into consideration) at the time of the calculation it is unlikely that both of these are the same; this can be true 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 that point in time 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 time.
- 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 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 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 open a further selection of which gas is being switched to, the list based on the available gases defined in the Equipment Tab. By right-clicking while over an existing marker, the menu extends adding options to allow deletion of the marker or to allow all markers of that type to be hidden.
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.
The moment the mouse points inside the *Dive Profile* panel, it expands and shows many data items. In this situation, the data reflect the time point along the dive profile indicated by the mouse (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, effective air depth (EAD), effective 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.
Many actions within _Subsurface_ are dependent on a context menu that is used mostly to manipulate groups of dives. The context menu is found by selecting a dive or a group of dives and then right-clicking.
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 that has an older date/time. Therefore you sometimes may need to renumber the dives. This is performed by selecting (from the Main Menu) _Log -> Renumber_. You 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.
If you dive regularly, the dive list can rapidly become very long. _Subsurface_ can group dives into _trips_. It performs this by grouping dives that have date/times that are 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 a grouped dive list with several trips (B, on the right):
Grouping into trips allows a rapid way of accessing individual dives without having to scan 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.
Once when the dives have been grouped into trips, you 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.
Normally, in the dive list, minimal information is included in the trip title. You can add much more information about a trip by selecting its trip title from the dive list. This shows a *Trip Notes* tab in the *Dive Notes* panel. Here you can add or edit information about the date/time, the trip location and any other general comment about the trip as a whole (e.g. the dive company you dived with, the general weather during the trip). 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 some of the edited information.
If you right-click after selecting a particular trip in the dive list, the resulting context menu allows several possibilities to expand or collapse dives within trips. This includes expanding all trips, collapsing all trips and collapsing all trips except the selected one.
When you right-click on a selected trip title in the *Dive List* panel, the context menu allows the merging of trips by either merging of the selected trip with the trip below or with the trip above.
If a trip includes five dives, you can split this trip into two trips (trip 1: top 3 dives; trip 2: bottom 2 dives) by selecting and right-clicking the top three dives. The resulting context menu allows you to create a new trip by choosing the option *Create new trip above*. The top three dives are then grouped into a separate trip. See below, the selection and context menu on the left (A), the completed action on the right (B):
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*. Typically this would apply to a case where you wish to delete workshop calibration dives of the dive computer or dives of extremely short duration.
You can unlink dives from the trip to which they belong. Select and right-click the dives to bring up the context menu. Then select *Remove dive(s) from trip*. The dives that have been unlinked now appear immediately above the trip to which they belonged.
Selected dives can be moved from the trip to which they belong and placed within the trip immediately above the currently active trip. Select and right-click the dives to bring up the context menu, then select *Add dive(s) to trip immediately above*.
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. Select and right-click the dive(s) to be adjusted. This brings up the context menu. Select *Shift times*. 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 forwards or backwards.
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. You can merge these dives onto a single dive by selecting the appropriate dives and right-clicking them to bring up the context menu. Then select *Merge selected dives*. It may be necessary to edit the dive information in the *Dive Notes* panel to reflect events or conditions that apply to the merged dive. The figure below shows the depth profile two such dives that were merged:
* Universal Dive Data format (UDDF). See http://uddf.org for more information. UDDF is a generic format that enables communication among many dive computers and computer programs.
In order to save the WHOLE dive log (i.e. all trips and dives), select *File* from the Main menu. To save in _Subsurface_ XML format, select _File -> Save as_. To save in UDDF format, select _File -> Export UDDF_.
In order to save only one or more dives or one or two trips, select the appropriate dives or trips in the *Dive List* panel. Then right-click the selected dives to bring up the context menu. To save in _Subsurface_ XML format, select _Save as_ from the context menu. To save in UDDF format, select _Export as UDDF_ from the context menu.
_Subsurface_ provides a simple interface to print your whole dive log or only a few selected dives, including dive profiles and other contextual information.
- 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.
- What gas partial pressure information is required on the dive profile? Select the appropriate information from the Main Menu: _File->Preferences->Graph_.
Now you need to select the print options. To do this, select _File->Print_ from the Main menu. The following dialogue appears (see the image on the left [A], below):
- Printing only the dives that have been selected from the dive list prior to activating the print dialogue, achieved by checking the box _Print only selected dives_.
- Printing in colour, achieved by checking the box with _Print in color_.
The _Ordering_ affects the layout of the page (or part of it) for each dive. The dive profile could be printed at the top of each dive, with the textual information underneath, or it could be printed with the textual information at the top with the dive profile underneath. Select the appropriate option in the print dialogue. See the image on the right (B), above which has a layout with text above the dive profile.
You can _Preview_ the printed page by selecting the _Preview_ button on the dialogue. After preview, changes to the options in the print dialogue can be made to give a layout that fits personal taste.
Now, select the _Print_ button in the dialogue. This activates the regular print dialogue used by your operating system, allowing you to choose a printer and to set its properties. Remember to set the print resolution of the printer to an appropriate value by changing the printer properties. Finally, print the dives. Above on the right (B) is an example of the output for one particular dive.
There are several settings within _Subsurface_ that the user can specify. These are found when selecting _File->Preferences_. The settings are performed in four groups: *Defaults*, *Units*, *Graph* and *Language*. All four sections operate on the same principles: specify the settings you wish to change, then save these using the *Apply* button. After applying all the new settings you can leave the settings panel by selecting *OK*.
** *Dives*: Here you need to specify the directory and file name of your electronic dive log book. This is a file with filename extension .xml. When launched, _Subsurface_ will then automatically load the dive log book specified.
** *Display invalid*: Dives can be marked as invalid (when you want to hide dives that you 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.
Here you can choose between metric and imperial measures of depth, pressure, volume, temperature and mass. By selecting the Metric or Imperial radio button at the top, you can specify that all units are in the chosen measurement system. Alternatively, if you select the *Personalise* radio button, you can select a mixture with some measurements being metric while others are in imperial measures.
** Gas pressure graphs: _Subsurface_ can display the pressures of the gases with which you dive. If you dive breathing air, then the only important gas is nitrogen. You can instruct _Subsurface_ to plot the nitrogen pressure during your dive. If you dive breathing nitrox, then you can select a graph of both the nitrogen and oxygen pressures during your dive. If you dive with trimix or heliox, you can select the display of the helium pressure as well. For each of these graphs you can specify a threshold value on the right-hand side of the panel. If any of the graphs go above this threshold level, the graph is highlighted in red, indication that the threshold value has been exceeded (see figure below).
** Ceiling: Ascent ceilings arise when a direct ascent to the surface exposes the diver to decompression sickness (DCS) and it is necessary to either ascend slower or to perform decompression stop(s) before ascending to the surface. _Subsurface_ can indicate these ceilings above which the diver should not ascend at a particular point in time (see the green-shaded areas in the figure in the section on <<S_DiveProfile,Dive Profiles>>) and in the figure below:
** If a _Maximum operating depth (MOD)_ or an _Equivalent air depth (EAD)_ applies to a dive profile, these can be shown by checking the appropriate boxes.
** If a _Maximum partial pressure of oxygen (maxPPO2)_ applies to dives, then this can be specified in the appropriate text box. In addition, if a _no-decompression limit (NDL)_ is to be shown in the *info* box, then check the appropriate box.
* *Misc*: Here you can set the _gradient factors_ used while diving. GF_Low is the gradient factor at deep depths 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 25/60 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. For more information see:
** link:http://www.rebreatherworld.com/general-and-new-to-rebreather-articles/5037-gradient-factors-for-dummies.html[Gradient factors for dummies, by Kevin Watts]
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 you can uncheck this checkbox and pick a language / country combination from the list of included localizations.
This section describes the functions and operation of the items in the Main Menu of Subsurface. Several of the items below are links to sections of this manual dealing with the appropriate operations.
=== File
- <<S_NewLogbook,_New Logbook_>> - Close the currently open dive logbook and clear all dive information.
- _Open logbook_ - This opens the file manager in order to select a dive logbook to open.
- _Save_ - Save the dive logbook that is currently open.
- _Save as_: - Save the current logbook or the currently selected dives within the present logbook under a different filename.
