Everything you enter stays on this device. There's no account, no server, no cloud sync. Dive logs, certificates, signatures, contacts, income — all of it lives only in this browser/app, on this phone.

Nothing leaves this device unless you choose to send it. Sharing a dive with your supervisor, generating a QR code, or exporting a backup are the only ways data goes anywhere — and you trigger each one yourself.

Signed dives use a real cryptographic signing key, generated automatically on this device the first time you need it. The private half never leaves your phone unless you deliberately back it up (Supervisor Profile → Signing security) — treat that backup code like a password, since it's what lets a device sign as you.

Face ID / fingerprint confirmation is optional and only guards the signing step (Supervisor Profile → "Require Face ID / fingerprint to sign") — it's not a lock on the app itself. See below for that.

A few features do call the internet — gold price, currency exchange rates, map tiles for the dive-location map, and sea conditions (GPS + public weather data, only if you turn that on in Live Dive). These only send generic requests (e.g. "what's the EUR price today"); none of your personal or dive data is sent to them.

There's no PIN or password on the app itself. Anyone who can unlock your phone can open this app and see everything in it — including drawn signatures and, unless you enabled Face ID/fingerprint above, sign a dive as you. If that matters to you, use your phone's own lock screen (Face ID, fingerprint, passcode).

Back up regularly. Since nothing is stored anywhere else, losing the phone, uninstalling the app, or clearing browser data means losing this data too — unless you've exported a backup (Settings > Backup & Restore) and, separately, your signing key backup if you sign dives.