Comparison
Apnea CWT vs inDepth Apnea: freediving apps for Garmin compared
Apnea CWT and inDepth Apnea are both freediving apps for Garmin watches. Apnea CWT is the well-known one, with two clean data screens, automatic dive switching and a buddy mode. inDepth Apnea Blue does all that too, then looks after what happens between dives: five surface-rest safety models, a dive history on your wrist, graphs of every dive on your phone, and marked spots on a map. Here's what each app does well, where they differ, and which one suits your training.
Updated
What does Apnea CWT do well?
Apnea CWT, by developer Charles Rincheval (apnea.me), calls itself "the vertical freediving app". It's a Connect IQ app for constant-weight training that shows your surface time, immersion time, heart rate, current depth and vertical speed at a glance, and switches to an immersion view by itself when you dive. It does a few things inDepth doesn't:
- A buddy mode that times your partner's immersion and counts their dives on a separate page. Handy on the edge of the pool or on the platform.
- Cadence vibration alerts: the watch buzzes at a set interval (from 10 s to 2 min) during immersion and recovery, so you can feel the rhythm of the cycle without looking.
- A wider watch list that includes Forerunner, Venu and Vivoactive models. That said, apnea.me's own compatibility list marks most of those as "not fully functional" because of Garmin's firmware depth cap.
It's a compact app with a long history, maintained in English and French since 2019. One practical difference is price: Apnea CWT is a paid app, listed at €12.00 per watch, while inDepth Apnea Blue is free, with no purchase, no ads and no subscription, on as many watches as you like. If all you want is two screens and nothing else, Apnea CWT is still a perfectly reasonable pick.
Where does inDepth Apnea go further?
inDepth Apnea Blue starts from a different question. Two screens tell you what's happening right now. They don't tell you whether it's safe to dive again, and that gap between dives is where inDepth puts most of its effort:
- Five surface-rest models. After every dive, the surface screen tells you how long to rest and counts it down. You can choose 2× dive time, 3× dive time, Adaptive (AIDA 4 guidance), Taravana (a model that tracks nitrogen building up over the session, with conservative levels) or Molchanovs (the bar × dive-time rule). Apnea CWT shows your surface time, but it doesn't tell you whether it's long enough.
- A dive history on the wrist. The watch keeps your recent sessions, a session summary (deepest, longest, number of dives, intervals) and a look at each dive with a second-by-second depth graph, descent and ascent rates, hang time and bottom heart rate. You don't need your phone to check your last dive.
- A free phone app and browser logbook. Every session syncs over Bluetooth to the inDepth app (iOS and Android). You get depth, heart rate and velocity graphs for each dive, session notes, annotations (LMC, samba, early turn…), personal-best trends and your full logbook on the web. You can export to CSV or FIT, and back up and restore everything.
- Hang detection. inDepth spots your hang at the bottom plate and highlights it in the dive profile. That's the number that tells you whether your CWT session actually did any work.
- GPS spot marking. Mark a reef, wreck, entry point or hazard with a labeled GPS position. Your spots sync to the phone map and to Garmin Navigate.
- Configurable depth alarms. Five alarm slots plus a target depth, each with its own direction, sound and vibration, and a preview so you know what it'll feel like. That's a lot more than a single over-depth alert.
- Pool apps too. inDepth Apnea Pool covers dynamic apnea (DYN, DYNB, DNF, STA). It counts your turns, times every length, shows heart-rate charts on your wrist, and runs workouts you build on your phone.
Apnea CWT vs inDepth Apnea Blue: side by side
| Apnea CWT | inDepth Apnea Blue | |
|---|---|---|
| Price | €12.00 per watch (paid) | Free: no purchase, no ads, no subscription |
| Live depth, surface time, dive counter | Yes | Yes |
| Automatic surface/immersion switching | Yes | Yes, adjustable dive-start depth (0.5–3 m) |
| Surface-rest safety models | No | 2×, 3×, Adaptive (AIDA), Taravana, Molchanovs, Manual |
| Dive log on the watch | Session maxima + upload for website charts | Last 10 sessions with per-dive graphs, rates and hang time |
| Phone app | No | iOS and Android logbook, trends, annotations, backups |
| Web logbook | Charts after activity upload | Full logbook editing, trends, spots map, FIT/CSV export |
| Depth alarms | One over-depth alert + dive-detection depth | 5 alarms + target depth, per-alarm audio/vibration |
| Hang detection | No | Yes, per dive |
| GPS spot marking | No | Labeled marks, synced to the phone and Garmin Navigate |
| Buddy mode | Yes | No |
| Dynamic apnea app | Separate Apnea DYN app | inDepth Apnea Pool: DYN, DYNB, DNF, STA |
| Devices | Fenix 3–8, Descent Mk1–Mk3, Forerunner, Venu, Vivoactive (many marked not fully functional) | Fenix 5–8, Descent Mk2/Mk3 (all fully supported) |
| Languages | English, French | English |
| Distribution | Sideload from apnea.me (not on the Connect IQ store) | Free installer for macOS/Windows over USB, or manual sideload from in-depth.app |
Do both apps have the same depth limits on Garmin watches?
Yes. On several watch families, Garmin's firmware caps the depth that any Connect IQ app can see: near 3 m on the Fenix 7 and the Descent Mk2/Mk3, and near 7 m on Fenix 6-class hardware. Neither developer can fix that, because it's Garmin's policy. What differs is how each app deals with it. On a capped watch, inDepth tells you the measured ceiling for your watch and switches off the safety models that need depth, instead of showing you a dive profile that stops at 3 m. The measured Connect IQ depth table lists every watch we've put on instruments. On the Fenix 5, Fenix 5 Plus and Fenix 8, both apps read true depth.
inDepth Apnea Blue is a freediving aid. It isn't a medical device, and it doesn't replace a trained buddy watching you. No algorithm takes away the risks of freediving. Never dive alone, always follow the one-up-one-down rule, and treat every rest recommendation as a minimum.
When is Apnea CWT still the right choice?
- You dive with a Forerunner, Venu or Vivoactive. inDepth Blue, the depth app, doesn't run on those.
- You want a buddy mode on the watch to time your partner's dives.
- You want the app in French.
If you dive constant weight on a Fenix or Descent, and you want your watch to tell you "how long until my next dive?" as well as "when did the last one end?", install inDepth Blue and see how it does on your own sessions. It's free to try, and your dives stay on your own devices.
How do you get inDepth Apnea?
Grab the free installer for macOS or Windows from the download page and plug in your watch over USB. The installer puts the app on your watch in about a minute. You'll find the supported watches on the help page, and the inDepth Blue user guide walks you through your first session.