Subsurface-mobile v2 user manual


Subsurface-mobile USER MANUAL

Manual authors: Willem Ferguson, Dirk Hohndel

Version 2.1.5, December 2018

Welcome as a user of Subsurface and Subsurface-mobile, advanced dive logging software with extensive infrastructure to describe, organize, and interpret scuba and free dives. Subsurface offers many advantages over other similar software solutions, including compatibility with Windows, macOS, Linux (many distributions), Android and iOS. In addition, Subsurface is open-source software that allows downloading dive information from many dive computers.

1. Introducing Subsurface-mobile

Subsurface-mobile is a 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 desktop 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:

  • Download and storage of dive log information using the Subsurface cloud.
  • Viewing this information on a mobile device.
  • Manually creating and adding new dive records to your dive log.
  • Download dive data directly from many dive computers.
  • Editing many of the dive log data fields, e.g. dive-master, buddy, equipment or notes relating to a dive.
  • Recording, storing and applying GPS positions of dives.
  • Viewing the localities of recorded GPS positions and of dives on a map.

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 inability of accessing some types 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.

2. Installing Subsurface-mobile on your mobile device

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.

3. Using Subsurface-mobile for the first time

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).

FIGURE: Mobile credentials screen

3.1. When NOT Using Cloud Storage

Tap the “No cloud mode” button. The app will not access the Subsurface cloud storage server to obtain dive log information. This means that dive log information is stored on the mobile device only. If no dives have been entered into the dive log yet (the usual case), an empty dive log is created.

3.2. Using Cloud Storage

The Subsurface developers provide a dedicated and free Internet cloud storage account that can be used for storing dive log information. This account can be created either from Subsurface on the desktop or from Subsurface-mobile using a mobile device; you can do full maintenance of a dive log from Subsurface-mobile alone. By using the same credentials with Subsurface-mobile and Subsurface for desktop, the Subsurface cloud storage allows sharing of a dive log between both (or even more than two) devices.

The dive data on the cloud are cached locally both on the mobile device as well as on the desktop -- it is easy to create backups of the data (for example in XML format) on the desktop: both mobile device and desktop keep a local copy of the data so that the dive log is always accessible, even without Internet connection. The Subsurface team never accesses a user’s dive data without explicit permission to do so, the data are not used for any purpose other than providing them to the user who created them. There are no ads and no harvesting / analysis of the data stored in the Subsurface cloud storage.

1) Enter an e-mail address and a password in the fields indicated on the screen (see image above). The e-mail address should be in lower case and the password should contain a combination of letters from the alphabet (upper and lower case) and/or numbers. Tap the “Sign-in or Register” button. If you have already set up an account from the Subsurface desktop application, enter the same credentials here. Once the dive list has been downloaded from the cloud, Subsurface-mobile usually works only with the the local copy on the mobile device. This avoids long delays or even failure of operations if there is a bad (or no) internet connection, a situation fairly common at many dive sites. Once registered, Subsurface-mobile remembers the cloud credentials and it is not necessary to provide these again when launching the program.

2) If this is a new cloud account, a PIN screen will open (see image on right, above). A PIN is e-mailed to the email address entered in the previous step. Enter this PIN into the field indicated and tap the Register button. The user information is stored on the cloud server and access to the cloud is enabled. In this case the dive list is initially empty. Start entering dives in the dive log or download dive information from a supported dive computer.

The dive log can be updated automatically. If there is Internet connectivity, Subsurface-mobile accesses the cloud-based dive log to verify that the local copy of the dive log is still the same as the log in the cloud server. If not, the local copy and the copy on the server are synchronized.

3.3. Changing the existing login credentials on the Subsurface cloud

The login credentials can be changed, for example to work with multiple accounts. See the section on Changing to a different Subsurface cloud account.

4. Menu Structure and User Interface

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.

FIGURE: Action Button

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

For 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:

  • Tap the “hamburger” symbol in the lower left corner of the screen (easy to reach for hand held devices)
  • Swipe towards the right across the left edge of the screen
FIGURE: Dive management sub-panel

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 sub-menus accessible.

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

5. The Dive List

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 the Details View for that dive including the dive profile, notes and additional information.

FIGURE: Dive list screen

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.).

6. Filter the dive list

Use this action button:

FIGURE: Filter button

at the bottom of the dive list to perform filtering of the dive list (see image above).

FIGURE: Filter

By default, all the dives in the dive log are shown in the dive list. After several years one’s dive log can become quite long and, sometimes, one would like to list only the dives of a particular type, e.g. those at a particular dive site or those with a specific buddy or dive master. Use the Filter to achieve this. The filter mechanism searches through all the information for each dive, looking for one or more key words. Only the dives containing these key words are listed in the dive list. In the Settings screen there two options that affect the way the filter searches for appropriate information. Firstly, one can select Match filter case sensitive which causes the search of key words to be case sensitive. Secondly, one can select Include notes in full text filtering. If this option is not selected, the filter does not search through the dive notes for key words. Selecting the Filter action button brings up a text box at the top of the dive list. Type the key words to be searched for. In the image on the left, the dive list has been filtered for the word “Nitrox” and 265 dives were found containing this word as a tag. For each trip in the dive list the number of dives containing “Nitrox” as a tag is shown. To clear the filter, remove the key words from the text box and select the Filter action button to switch off filtering.

7. Viewing the locations of all dives in the dive list

FIGURE: Map of all dive sites

The locations of all dives in the dive list can be viewed from the Main Menu by selecting the Map option. A satellite image of the world is shown. At that scale no dive sites are shown. If one zooms into a particular region of the world the dive sites appear, indicated by red flags. Zooming in even closer indicates the names of each of the different dive sites.

8. Viewing the location of a dive on Google Maps

FIGURE: Map of dive site

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 on left).

9. Edit a particular dive

FIGURE: Dive edit screen

At the bottom of the Dive Details screen the action button is a pencil. 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 on left). 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.

10. Manually adding a new dive to the dive list

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 Dive management → 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 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.

FIGURE: Manual dive entry screen

11. Copy dive information from one dive to another

When editing dives it is possible to transfer information from one dive to another. For instance, when diving with the same buddy and the same equipment configuration during a particular dive trip it can be efficient to simply copy all this information from the previous dive into the dive that is being edited. Currently a standard list of dive information is copied to the clipboard:

Divemaster, Buddy, Suit, Tags, Cylinders, Weights.

Copy and paste dive information is performed on the Dive List. Long-press on a dive. A panel with three icons appears on top the selected dive :

FIGURE: Copy/Delete dive information

To copy the above information to the clipboard, select the leftmost of the three icons. A “Copy” notification briefly appears on the screen. Now long-press the dive into which the copied information needs to be pasted. The same three icons appear on the target dive. Select the middle icon. A “Paste” notification briefly appears on the screen. This completes the copy-and-paste action. Continue by reviewing this new (pasted) information by manually editing the target dive.

To choose what dive details to copy, long-press the copy button. This will open up a configuration page where you can toggle the details you want to copy over to the destination.

12. Deleting a dive

Delete a dive from the dive list by long-pressing a dive until a red dustbin appears on the right-hand side (see image above). 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.

To choose what dive details to copy, long-press the copy button. This will open up a configuration page where you can toggle the details you want to copy over to the destination. By default, the following fields are copied:

FIGURE: Undo delete dive

13. Download dives from a dive computer

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 dive computer, the vendor is Shearwater and the Dive computer name is Petrel(see image on the left, below). Caveats: The download feature in smartphones 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 Bluetooth dive computers that are supported in Subsurface on the desktop. Both Android and iOS devices allow direct download of dive data from a handful of Bluetooth LE enabled dive computers. Use the Vendor name and Dive Computer drop-downs to pick the correct dive computer. When downloading from multiple different dive computers, shortcut buttons appear below the drop-downs to easily switch between them. In the Settings menu one can remove these buttons, a useful feature for removing buttons of dive computers that are not used any more. Achieve this by selecting the option Forget remembered dive computers in the Settings menu. After all these caveats, let us proceed with download.

For USB FTDI 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. Not all Android devices support OTG cables and even on some devices that do support those cables in general, Subsurface-mobile can in some cases still not access a dive computer through a serial port due to limitations in the Android and iOS operating systems.

Subsurface remembers the settings for dive computers that have been successfully used (image on right, below). These appear as buttons under a heading “Previously used dive computers“. Select the appropriate button. Having connected the USB dive computer to the Subsurface computer and having selected the appropriate vendor and dive computer, ensure that the Connection text box shows “FTDI”.

For BLUETOOTH/BTLE dive computers: The process for Bluetooth download is slightly different between Android and iOS. 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 BTLE requests. However, 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 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 many Android devices, the Settings → Bluetooth tool of Android is probably appropriate. Subsurface-mobile performs communication using both Bluetooth and Bluetooth-low-energy (BTLE). The appropriate choice of Bluetooth communication is often made by the software and the user need not be concerned with this. For dive computers with both Bluetooth and Bluetooth-low-energy (BTLE), a separate button is presented on the download screen for each mode of communication, allowing a choice. Use the Connection value to distinguish between the two options. In the image on the right, below, there are three buttons labeled “Shearwater Petrel 2”. These represent two Shearwater Petrel dive computers, one of which can communicate in both Bluetooth as well as BTLE. The Connection information indicates that the Petrel with no BTLE is selected.

DOWNLOAD: With communication between dive computer and Subsurface-mobile having been set up, tap the Download button. Be patient because the download can take a few minutes. As a matter of fact, a complete first download from some dive computers can take 45 minutes or longer. The downloaded dives appear in the bottom part of the screen, the most recent dive at the top (see image on right, below).

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.

FIGURE: DC download screen

14. Dive log management

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 of 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 tapping the “Hamburger” icon at the bottom left of the screen). Tap the option Dive management, enabling a number of options:

14.1. Add new dive manually

This is described above under the section dealing with Manually adding a new dive to the dive list.

14.2. Download from DC

This is described above under the section dealing with Download dives from a dive computer.

14.3. Apply GPS fixes

This is described in the following main section, below.

14.4. Manually sync the dive log with the Subsurface cloud storage

Upload the dives contained on the mobile device to the Subsurface cloud storage by tapping the option Manual sync with cloud. This synchronizes the local changes to the dive log with the cloud storage. It also downloads changes made to the dive log using another device or computer and stored in shared cloud storage.

14.5. Enable cloud auto sync

By default Subsurface-mobile runs offline and only syncs the dive list with cloud storage when explicitly told to do so (see above). You can choose to always sync with the cloud servers. This is not recommended unless you are in an area with a fast and reliable internet connection, as otherwise Subsurface-mobile might appear to hang between operations as it tries to connect to the cloud server. Selecting Enable cloud auto sync causes the local dive log to be synchronized with the copy in the cloud every time that Subsurface-mobile is closed.

15. Recording dive locations using GPS

The fact that most smartphones have GPS facilities allows Subsurface-mobile to record the locations of dives. IMPORTANT: GPS-derived coordinates on a smartphone are not always accurate and can have an error greater than 1 km. GPS accuracy is determined by the hardware and software of the smartphone as well as by the GPS settings selected within Android/iOS. As of Android V6 select Android Settings → Communication → Location → High accuracy. If the smartphone is taken on the 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:

15.1. Configuring the GPS service

From the Main Menu, select Settings screen which has a section for configuring the GPS service (image below). GPS location data are collected at regular intervals, e.g. every 5 minutes, or at regular distances, e.g. after the boat has moved more than 200m, or a combination of both of these approaches. Provide the appropriate information and tap the Back button. The program is now ready to collect GPS positions.

FIGURE: GPS configure

15.2. Collecting GPS positions


On the Main Menu select GPS → Run location service. Subsurface-mobile starts to collect GPS locations automatically, following the preferences specified as described above. While the GPS location service is running, all menus have a GPS symbol at the bottom of the menu, indicating that the service is active. After return from the dive trip, deactivate the collection of GPS data by tapping the option GPS → Disable location service. The GPS symbol at the bottom of all menus disappears.

15.3. Viewing GPS data

From the GPS submenu select Show GPS fixes. This brings up a list of GPS positions obtained by the location service (image below). Two actions are possible for each of the locations, enabled by dragging the right part of a location to the left. This exposes two options. Tapping the dustbin deletes this particular GPS location. Tapping the teardrop-shaped icon (actually a Google Maps pin) opens up Google Maps with a pin indicating the exact map position of the GPS record being viewed. The two above options can be hidden by drawing the GPS record to the right.

FIGURE: GPS management

15.4. Applying GPS data to dives in the dive log

Assuming that all the dives have been entered into the dive log or have been downloaded from the Subsurface cloud, apply the GPS positions to these dives. GPS positions can only be applied to dives in the dive list. From the Dive management sub-panel, tap Apply GPS fixes. The dive list contains the start and end times of each dive. Now, Subsurface-mobile applies the first GPS position that falls within the dive period of each dive. This results in a GPS position for each dive that is saved as part of the dive log.

16. Specifying the settings for Subsurface-mobile.

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.

16.1. Changing to a different Subsurface cloud account

Some users have more than one Subsurface cloud account and have a need to switch between accounts. Tap Settings on the Main menu and scroll to the section titled Cloud status (see image below). Tap the Change button. This opens the Cloud credentials screen. change the credential information, then tap the button Sign-in or register. The appropriate dive list is shown.

FIGURE: Settings: Cloud & Theme

16.2. Changing the color theme of Subsurface-mobile


Subsurface-mobile has three color schemes to please users with different tastes (see image above). This user manual shows the default color scheme, comprising blue colors. Change to a pink or a dark color scheme by opening the main menu, tap Settings, and scroll to the section with heading Theme (see image above). Select the appropriate color theme by dragging the appropriate slider on the right-hand. On the left is the dive list after selecting the Pink theme.

16.3. Configuring the GPS webservice

The Settings screen allows one to set up the way in which GPS positions are collected during dives. See the section on Configuring the GPS service.

16.4. Activating the Developer sub-menu

The information in the subsurface.log generated while running Subsurface-mobile, plus some additional information for understanding the screen rendering of dive information as well as the way in which Subsurface-mobile processed information during a specific occasion while running the app (see section below) is available through a Developer menu at run time. Activate (or deactivate) this menu item on the Main Menu by dragging the slider switch in the Settings screen. If Display developer menu 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.

16.5. App log

This option shows the messages that Subsurface-mobile generates while running. While most users are not aware of these messages, they are often crucial in detecting any abnormal behavior of the app. The App log can be found in the root directory of the local storage of the mobile device.

16.6. Theme information

This option provides a wealth of information about the screen characteristics of the mobile device and the font characteristics used by Subsurface-mobile.