Loggerfish › Switching from another app
A Subsurface alternative for iPhone: your log, your charts, your map
Subsurface is a capable, free, open-source logbook. Loggerfish is the one that opens in your iPhone’s browser with nothing to install: bring your Subsurface log across in a minute, then see your own diving in charts and on a map, in five languages.
What Subsurface lists
Subsurface presents itself as free and open source. It runs on Windows, macOS and Linux, with Subsurface-mobile for iOS and Android. It lists dive computers from about 40 makers that it can download from, by USB, Bluetooth or Bluetooth LE, and its iPhone app downloads from many Bluetooth LE dive computers.
Checked 22 October 2026 · Source: subsurface-divelog.org · Subsurface supported dive computers · Subsurface user manual · App Store: Subsurface-mobile
What you get with Loggerfish
| What | What you get | Plan |
|---|---|---|
| Export | Excel, UDDF and a full backup, whenever you like | Free, for good |
| Import | SSI spreadsheet, Garmin .fit, Subsurface logs, UDDF, any spreadsheet; a type-or-paste grid for the PADI app | Free |
| Sync | Your logbook on all your devices | Free |
| Offline | Log a dive with no signal; it syncs when you are back | Free |
| Planning aids | Nitrox, no-stop limits, minimum gas, weighting, gas blending, best mix (aids, not a dive computer) | Free |
| Analysis | SAC trend, forecast against your yearly target, seasons, conditions and gas, sightings life list | Pro |
| Dive-site maps | Your dives on a map, and sites near yours | Pro |
| Dive passport | Certification cards, insurance, medical fitness and your last dive on one screen that works with no signal; kept on your device, not uploaded | Pro |
| Dive computer download | Download dives over Bluetooth from a Mares Sirius or a Shearwater Peregrine TX on iPhone; other dive computers come in as files | Pro |
| Languages | English, German, Spanish, French, Polish | Free |
Pro is €4.90 a month or €29 a year, with 14 days free on every new account. Prefer to pay once? Lifetime Pro is €99, for the first 500 buyers or until 90 days after launch. Logging, import, export and sync are free either way.
One difference to weigh: on iPhone, Loggerfish downloads from two dive computers, the Mares Sirius and the Shearwater Peregrine TX, over Bluetooth. Other dive computers are not supported yet, so for those it reads files: Garmin .fit files, Subsurface logs, UDDF and spreadsheets. If downloading straight from your own dive computer matters most to you, check that it is one Loggerfish supports; if it is not, Subsurface does that.
Bringing your Subsurface log across
- Find your Subsurface log file. Loggerfish reads .ssrf files and the .xml that Subsurface saves.
- Open Loggerfish. Importing needs no account: the file is read on your own device.
- Open the import, choose the file, and read the preview. Cylinders, profiles and gas changes come across with each dive.
- Confirm the import.
Your Subsurface file is not touched, so you can keep using Subsurface alongside Loggerfish.
Bring your Subsurface log across in a minute
Free to start, no card. Your logbook, and every export of it, stays yours on every plan.
PADI, SSI, MySSI and Subsurface are names of their owners, used here only to say which app we mean. Loggerfish is not affiliated with, endorsed by or sponsored by any of them. What this page says about them is taken from their own public pages, listed beside each statement with the day it was checked; apps change. If something is out of date, write to support@loggerfish.com and we will correct it.