Solved (UPDATE!): import old dive logs into the Suunto app (from Subsurface, divelogs.de, or any logbook)
Like many here, I had years of dives from an old Suunto HelO2 sitting in Subsurface/divelogs.de and no way to get them into the Suunto app when I bought a new Suunto watch. Every forum thread on this ends the same way: “import to DM5 first, then SuuntoLink” — and then people get stuck, because DM5 only accepts formats nothing else can export, and even when you do get dives into DM5, SuuntoLink imports zero of them.
Here’s what we found by reading SuuntoLink’s import code: SuuntoLink never reads DM5 or its database at all. Its “Import dive logs” feature just scans the folder you pick for .sml files — the per-dive log files that Windows DM5 happens to leave behind — parses each one, and uploads it to your Suunto account. No SML files in the folder, no import. That’s the whole mystery.
Which means DM5 can be skipped entirely. One script converts a Subsurface logbook straight into SML files that SuuntoLink accepts:
https://github.com/974c426jdy-svg/Import-old-dive-logs-into-the-Suunto-app-
The pipeline: get your dives into Subsurface (it imports from divelogs.de, UDDF, MacDive, Diving Log, old Suunto SDM files, and dozens of dive computers) → export as Subsurface XML → python3 ssrf2sml.py mydives.ssrf → SuuntoLink → Import dive logs → point at the output folder. Done. Full depth profiles, temperatures, gas mixes, and tank pressures all come through — verified with a 56-dive logbook (2014–2025) now living in the Suunto app. Plain python3, no dependencies, free and open source.
Good to know: always test with 1–2 files first (uploads go straight to your live account); re-importing is safe since the server skips duplicates by date+time; imported dives show in your app diary and count toward totals but don’t sync down to the watch (Suunto watches only display dives they recorded themselves — that’s by design, for all imports); and the repo also includes tools for getting dives into desktop DM5 itself, if you use it as a logbook, including a fix for its silently-dropped tank pressures.
Tested on macOS; Windows should behave identically since SuuntoLink works the same way there. Would love confirmation from a Windows user.
Hope this saves someone the two weeks it cost me.
