Professional dive computer for Apple Watch Ultra. Bühlmann ZHL-16C decompression algorithm, real-time NDL, nitrox support — right on your wrist.
Free · 1 dive/day · Pro £4.99/mo for unlimited
Built for recreational divers — Open Water through Advanced, including Nitrox certified. Replace that bulky wrist computer you only wear diving.
The same decompression algorithm used by Shearwater and Subsurface. 16 tissue compartments, gradient factors, fully validated.
Apple Watch Ultra's EN13319-certified depth sensor at ≥1Hz. Current depth, max depth, and ascent rate always visible.
No Decompression Limit calculated continuously. Colour-coded: green → amber → red as limits approach. Haptic alerts at 10 and 5 minutes.
Configure EAN21–40% with automatic MOD calculation at your chosen PO₂ limit. CNS O₂ and OTU tracking included.
Conservatism from −2 to +2 maps to GF presets (20/70 → 60/95). Tune to your training agency's recommendations.
Digital compass with bearing lock — tap to set, deviation arrow shows when you drift off course. Essential for navigation dives.
Automatic safety stop at 5m with countdown timer. Full decompression stop calculation if you exceed NDL, with TTS display.
Dive data stays live even in always-on mode. Glance at your depth and NDL without raising your wrist — critical underwater.
Dives sync automatically to your iPhone. Depth profile charts, dive notes, buddy tracking, site names, star ratings.
Export your full logbook in UDDF format — compatible with Subsurface, MacDive, and other dive logging software. Your data, your choice.
NDL calculator, MOD calculator, surface interval and no-fly time tools — all powered by the same Bühlmann engine.
Post-dive flying restriction calculated from tissue loading. Visible on Watch after a dive and in iPhone summary.
One glance. Everything critical. Depth in the largest type possible — readable through a mask at arm's length.
No hunting for information. Colour communicates safety state instantly — even in poor visibility.
| Ascent too fast | Long buzz |
| NDL <10 min | Double buzz |
| NDL <5 min | Triple buzz |
| Deco obligation | Continuous |
| MOD exceeded | Continuous |
| Safety stop (5m) | Single buzz |
| Pelagic | Oceanic+ | DIVEROUT | |
|---|---|---|---|
| Price | Free + £4.99/mo | £9.99/mo | £7.99/mo |
| Bühlmann ZHL-16C | ✓ | ✓ | ✓ |
| Gradient factors | ✓ | Limited | ✓ |
| Nitrox | ✓ | ✓ | ✓ |
| UDDF export | ✓ | ✓ | Partial |
| Watch standalone | ✓ | ✓ | ✓ |
| Always-on display | ✓ | ✓ | ✗ |
| AI colour restore | Phase 2 | ✗ | ✓ |
| Buddy tracking | Phase 2 | ✗ | ✓ |
| Free tier | ✓ 1 dive/day | ✗ | ✗ |
Perfect for occasional divers
For regular divers
Much less than that dedicated dive computer you wear once a month.
Pricing shown in GBP. Billed monthly. Cancel anytime.
Full instructions for every screen, setting, and safety feature. Whether you're a first-time user or an experienced diver.