Subsurface-mobile is a more limited mobile version of Subsurface aimed at Android and iOS smartphone and tablet devices, allowing viewing, entering, sharing, and storage of dive information at dive sites where a larger computer is not useful. While the desktop version of Subsurface shows much more detailed information for each dive, the mobile version allows a more accessible dive log on a dive trip, useful for proving dive experience to dive shops or to review previous dives. Subsurface-mobile also allows the gathering of GPS locations where dives are performed.

Users of Subsurface-mobile typically use the mobile app as a companion to the laptop/desktop version of Subsurface, sharing dive information between the mobile and the desktop versions. However Subsurface-mobile can also be used independently of the desktop version and does not require the use of cloud storage.

Subsurface-mobile allows:

These items are discussed in greater detail in the following text. Subsurface-mobile does not support download of dive data from all the dive computers that the desktop/laptop version can. This limitation is mainly caused by the ability to access different type of devices on the two mobile platforms. On Android, a subset of dive computers that use a FTDI USB interface or a Bluetooth / Bluetooth LE interface are accessible by Subsurface-mobile. On iOS, only Bluetooth LE based dive computers are supported.

Find Subsurface-mobile in the Google Play Store or the iTunes Store and install it. Please note that both stores also contain the older Subsurface companion app (used only for tracking GPS positions) - make sure you actually install Subsurface-mobile.

When you start Subsurface-mobile for the first time, a Subsurface splash screen is shown while the program loads. On some devices this may take several seconds. After loading, the Cloud Credentials screen appears (see image below on left).

At the bottom of many Subsurface-mobile screens is a round button that provides for several actions (see image below). The most common choice is indicated in a round colored action button (in the case below, edit a dive). Alternative actions are indicated in a white action bar. On Android devices, use the Android Back button for "cancel", "discard" or "back" actions. For example, when editing dive information, tapping the action button saves the changes while the Android back button can be used to cancel the edit without saving changes.

On iOS devices, on screens where a "back" action is enabled, a back arrow is shown in the top left corner of the screen.

In order to have a consistent experience between iOS and Android, Subsurface-mobile on Android does not use the traditional "hamburger" menu button in the top left or right corner of the screen to open menus. Instead, Subsurface-mobile uses a different user interaction philosophy based on the Kirigami framework developed by the Plasma developers. There are three ways to open the main menu:

The image above indicates some of the important features of the menu system. On the left is the main menu, activated as described above. On the right of the image are the items of all the submenus accessible.

All screenshots in this user manual are currently from the Android version. The iOS screens look fairly similar.

Most of the actions of Subsurface-mobile center around the dives on the dive list. While the dive list is loading from the cloud, a message appears at the bottom of the screen, indicating that the cloud is being accessed, after which the dive list is shown. Once the list is loaded you can scroll up and down through your dive history. To upload dives from a dive computer, tap the blue action button. If you wish to add a dive manually, tap the + button in the action bar (described below). Tapping an existing dive on the list brings up a display of Details View for that dive (see image on right below). This includes the dive profile as well as additional information and notes.

You can view other dives by swiping the Details view to the right (for the previous dive) or to the left (following dive). Using the Action Bar, it is also possible to delete the dive (tap the dustbin on the Action Bar) or to view the dive location on a map viewer (Google Maps on Android, the Google Maps web site on iOS; tap the GPS icon on the Action Bar.).

At the bottom of the dive details screen the action button is a pencil (image on right, above). Tapping the pencil button changes the page and enables edit boxes that allow modifying the existing dive information, e.g. adding text to the dive notes or changing the names or values of some of the information (see image below). It may be necessary to scroll the window to access all the information. At the bottom of the edit screen is a Save action button. Tap this to save the new information, after which the dive list screen is updated and shown. To cancel any edits, tap the Android Back Button or the application back button at the top left of the screen on iOS.

When the virtual keyboard is shown, to avoid screen clutter, the action button is hidden. Once you close the keyboard it is drawn again.

One can manually add a dive to the existing dive list. On the dive list tap the "plus" sign in the action bar, or use the main menu and tap Manage dives → Add dive manually. This opens a screen that is identical to the editing screen discussed above. When a dive is added manually, you cannot directly add a dive profile from a dive computer. However, if you do not use a dive computer, the duration, depth and several other bits of information about the new dive can be entered. The Action button at the bottom of the screen contains a disk symbol. Tap this to save the new dive. To cancel any edits, tap the Android Back Button. The left-hand image below shows a screenshot of a dive being created and the right-hand image shows the same dive in Details View.

The Details View of a dive has an Action Bar, including a dustbin. If this is tapped, the dive shown in the Details View is deleted. You have a brief opportunity to undo the delete by tapping the grey Undo button in the message that appears at the bottom of the screen (see image below).

You can also delete a dive from the dive list by long-pressing a dive until a red dustbin appears on the right-hand side (see image below). Tap the dustbin. The dive is deleted without asking any confirmation because Subsurface-mobile assumes that the combination of a long tap on the dive with another tap on the red dustbin is an unambiguous instruction to delete the dive.

The download deature supports only a limited number of dive computers. On Android devices these are typically dive computers using an FTDI interface using a USB OTG cable (but this is blocked on some Android devices by OS settings). Android devices also support all Bluetooth dive computers that are supported in Subsurface. And both Android and iOS devices allow direct download of dive data from a hand full of Bluetooth LE enabled dive computers.

The process for download is slightly different between the two OSs. In our testing we got the best results on iOS when the dive computer was in Bluetooth mode before Subsurface-mobile is started. On most dive computers this is done through a menu entry, others (like the Suunto models) always respond to BLE requests.

On Android devices, you should first establish a link between the Bluetooth or Bluetooth LE dive computer and the mobile device using Android utilities. See below for more details.

For USB dive computers, USB cables "normally" used for uploading dives to a desktop/laptop computer do NOT work: these cables usually have a full-sized ("Type A") male USB plug on one end which plugs into the USB port of a desktop/laptop computer. For downloads to a mobile device one needs a USB OTG (USB On-The-Go) cable. In most cases it is required to plug the USB cable "normally" used with the dive computer into a USB OTG cable which, in turn, plugs into the mini-USB (or sometimes a USB "Type C") receptacle of the mobile device. The OTG cable usually has a full-size ("Type A") female receptacle at one end which accommodates the full-sized male plug of the USB cable "normally" used (see image below). This means that two cables are used to connect the dive computer to the mobile device.

Please note that not all Android devices support OTG cables. And even on some devices that do support those cables in general, Subsurface-mobile still in some cases cannot access a dive computer through a serial port.

For Bluetooth-equipped dive computers and Android devices, establish a Bluetooth connection between the dive computer and the mobile device. Use the tools on the mobile device to achieve pairing between the Bluetooth dice computer and the mobile device. For of Android devices, the Settings → Bluetooth tool is probably appropriate. Ensure pairing of the dive computer and mobile device. Subsurface-mobile performs communication using both Bluetooth and Bluetooth-low-energy (BTLE). The appropriate choice of Bluetooth communication is made by the software and the user need not be concerned with this.

With pairing between dive computer and Subsurface-mobile having been set up, dive download is simple. From the main menu, tap Manage dives → Download from DC. A screen is shown requiring that the user specify the names of the vendor and model of the dive computer. For instance, when using a Shearwater Petrel 2 dive computer, the vendor is Shearwater and the Dive computer name is Petrel 2. From the two dropdown lists at the top of the screen, select the correct vendor and dive computer names (see image on the left, below).

Now tap the button labeled Download. The downloaded dives appear in the bottom part of the screen, the most recent dive at the top (see image on right, below). Be patient because the download can take a few minutes. As a matter of fact, a complete first download from some dive computers has been shown to take 45 minutes and longer.

After the download, each dive has a check-box on the left hand side, used for selecting which dives you want to be added to the Subsurface-mobile dive list: dives that are not checked are ignored. With the appropriate downloaded dives having been checked, tap the button at the bottom left labeled Accept. All the selected dives appear on the Subsurface-mobile dive list. The downloaded dive information can now be edited as described in the section above Edit a dive.

In the Details View, the Action Bar at the bottom has a GPS pin on the left hand side. Tap that pin and the dive site is shown in Google Maps. Close Google Maps by using the Android Back button or tapping on the Subsurface-mobile link in the top left corner on iOS.

Alternatively, the Details View has a button at the top right hand marked Map it. Tap this button to open Google Maps showing the dive site (image below).

A central part of Subsurface-mobile is the ability to store the dive log using the Subsurface cloud storage. This provides security against loss or damage to the dive information in a local copy and allows the desktop version of Subsurface to access changes made using the mobile device. This ability is accessed through the main menu (by dragging the Action Button to the right, or by tapping the "Hamburger" icon at the bottom left of the screen). Tap the option Dive management, enabling a number of options:

The fact that most smartphones have GPS facilities allows Subsurface-mobile to record the locations of dives. If the smartphone is taken on the dive boat during a dive, locations will be automatically recorded at regular intervals. These locations can then be applied to dives in the dive list. Here is how it’s done:

The Settings screen allows the customization of Subsurface-mobile. Many of the settings involve dragging a slider switch to activate or deactivate a particular setting.

If the Developer submenu has been activated in the Settings screen, the Main menu has a Developer item. By tapping this one has two options that are relevant within the context of program development and debugging.