Deepline: Apnea & Freediving

Find your breath. Deepline pairs a calm apnea trainer — CO2 and O2 tables plus box breathing — with a beautiful freediving logbook. Fully offline. The numbers are the heroes, and the water goes still when you hold.

Deepline is for freedivers, spearfishers and snorkelers — and for anyone who wants a quieter way to train their breath.

Train your breath hold
- CO2 and O2 apnea tables, auto-built from your personal max
- Box breathing for daily calm and pre-dive focus
- A still, high-contrast timer made for wet hands and bright sun
- The water stays motionless during every hold — nothing to distract you

Log every dive
- Depth, breath-hold time, discipline and conditions
- A GPS pin for every spot
- Your full freediving logbook, kept on your device

See your progress
- Watch your breath-hold time grow, session after session
- Personal records, kept simple

Calm by design
- A signature living-water interface, not another stopwatch
- No clutter, no noise, no emoji
- Works fully offline — no account, no sign-up, your data stays yours

How it works
1. Measure your baseline breath hold
2. Train with CO2 / O2 tables and box breathing
3. Log your dives and watch your progress deepen

Free to use. Your breath, your data, your line to the deep.