Importing your logbook from Subsurface

Subsurface is the dive log a great many divers trust with their whole history, and bringing one of those logbooks into Divebase has been a long-standing request.

Today we're opening up support for importing your Subsurface logbook. Not a slice of it: the dives, their sites, their cylinders and the gas switches between them, the weights you carried, the people you dived with, your suit, and the depth profile of every dive your computer recorded.

Head to Import & Export, pick Subsurface, and hand it your divelog. In Subsurface that is File → Save as, which writes a .ssrf file. If you keep your log in Subsurface's cloud or a local git repository, save a copy to a file first and upload that.

Why not UDDF?

Subsurface can also export UDDF, and Divebase has imported UDDF for a while, so you might reasonably reach for it. Don't. We compared the same 31-dive logbook both ways, and Subsurface's UDDF export leaves a lot behind:

• No tank pressures at all. The native file carried 2385 pressure readings; the UDDF export carried none.
• No cylinder sizes, no gas roles, no weights, no dive guide, no suit, no tags.
• No CNS, no OTU, and no dive-computer events, so no gas switches and no setpoint.
• No record of which computer recorded the dive.

Its dive identifiers are regenerated on every export too, which means re-importing the same log would add every dive again rather than recognising the ones already in your logbook.

Reading Subsurface's own format avoids all of that, so this section is the one to use.

Two things worth knowing

Gas switches come in with their timing. Subsurface records the exact moment you switched to each gas, so every gas lands with the window it was actually breathed, not a guess. That is a first for a Divebase import.

Your dive computer comes along. Where the file names the recording computer, the dive's profile records its model, serial number, and firmware, and its decompression algorithm lands on the dive.

Re-importing is safe. Every dive is matched on the identity your computer gave it, so uploading a grown logbook next month brings in the new dives and leaves the rest alone.

One caveat: this importer is new, and Subsurface's format is generous. If a dive comes in looking wrong, tell us at hello@divebase.cloud and send the file if you can.

Bring your history home... and, as always, dive safe! 🤿