How to use inDepth Blue

Before your first dive

1. Install it. Use the inDepth desktop installer over USB — install help and troubleshooting. 18 Garmin models are supported: the Fenix 5, Fenix 5 Plus, Fenix 7, Fenix 8 and Descent Mk2 / Mk3 families. The Fēnix E is not supported — it is the one model in the series with no depth sensor.
2. Hold MENU → Settings and set three things:
   • Water type — Fresh or Salt. Salt water is ~2.5 % denser, and the wrong setting skews every depth reading by the same amount. Set it before the session, not after.
   • Units — depth in meters or feet, temperature in °C or °F.
   • Dive Start Depth — how deep counts as a dive (default 1.0 m). The range is 0.5–3.0 m on the Fenix 5, Fenix 5 Plus and Fenix 8 families, and 0.5–2.0 m on the Fenix 7 and Descent Mk2 / Mk3 — those watches only report depth to about 3 m through Connect IQ, so a deeper threshold would never trigger.
3. On a Fenix, turn off altimeter auto-calibration in the watch's own system settings — depth there is read from the barometer.
4. Optional: try it dry. Settings → Simulate a Dive runs a demo dive on dry land, so you can see the screens and hear your alarms before you get wet.

How deep your watch can actually read

The app reads depth from the watch's pressure sensor — and Garmin caps what a Connect IQ app is allowed to read on some models. This is the single most important thing to know before you rely on the app:

On the capped watches everything else still works — dive times, surface intervals, rest timers, alarms up to ~3 m — but a 30 m dive is recorded as ~3 m. It is a Garmin firmware limit, not something the app can lift, and it affects every Connect IQ app equally. For full-depth freediving on those watches, use the watch's own native dive or apnea mode. The best Garmin watch for freediving guide compares every model on exactly this.

A session, start to finish

1. Press START on the home screen to begin a session.
2. Dive. Dives are detected automatically — descending past your Dive Start Depth begins one, surfacing ends it. Very brief or very shallow detections (under about 4 seconds, or barely below the threshold) are treated as wave noise and discarded.
3. Surface. The watch drops you back to the Surface screen: time of day, your surface interval counting up, live heart rate, and your last dive's time and depth. A ring fills around the edge while you owe rest, then turns green with a buzz at READY. If Last Dive Summary (Settings) is set to On for 30 / 60 / 90 / 120 sec, that review opens automatically on top of Surface and disappears when the timer ends — any button press keeps it open. (This setting is not on the Fenix 5 / 5S; those watches always go straight to Surface, and Last Dive Summary is still reachable with DOWN.)
4. Review between dives if you like — DOWN for your last dive, DOWN again for the full dive log. The rest countdown keeps running behind you; reviewing never interrupts the session.
5. Finish with START (or BACK), then Stop & Save. On the Descents, Fenix 7 and Fenix 8 that menu is a compact overlay over the Surface screen; on the Fenix 5 and Fenix 5 Plus family it is full-screen. Same items either way. Discard asks first — “Discard session?” → Yes, discard / Cancel — whenever the session holds a dive or a marked spot, so one mis-press cannot lose your day. Cancel keeps everything. A session with nothing in it is discarded on a single press, and Stop & Save is never confirmed. If you have written a session note on your phone or in the browser (Settings → Session Notes) for today’s dive, that menu carries one extra row, Session Note, showing what you wrote.

The buttons

A small column of dots on the left edge flashes on each press to show which of the four screens you are on.

Settings worth knowing

Depth alarms

Five independent alarms plus a dedicated Target depth, each with its own depth, direction (descent or ascent), audio and vibration. Plan around the buzz, not the beep: a watch buzzer barely carries underwater, and vibration is the channel that reliably reaches you. Strong vibration plays the same pattern twice — it is longer, not harder.

A depth alarm is not a safety backstop. On the capped watches above, an alarm set deeper than ~3 m can never fire, and on any watch a deep alarm is not guaranteed to reach you. Dive as though the alarm might not come.

Surface Rest Alerts

How long to rest between dives: 2× / 3× Dive Time, Adaptive (AIDA), Taravana, Molchanovs or Manual. The three depth-driven modes are only offered on the watches whose depth reading is trustworthy (Fenix 5, Fenix 5 Plus, Fenix 8); the ~3 m-capped watches list 2×, 3× and Manual, and default to 2×. Rest is a recommendation — the watch never blocks a dive. There is a fuller explanation of each model in freediving surface intervals, explained.

Last Dive Summary

Off (default), or On for 30 / 60 / 90 / 120 sec. After you surface, the last dive's review can open itself for that long, then disappear. Any button press cancels the timer and leaves the page open. The row is absent on the Fenix 5 / 5S — those watches always return to Surface after a dive, but Last Dive Summary is still reachable with DOWN.

Heart rate

On (live readout on the surface screen), Record only (captured but hidden), or Off. With HR On, the heart icon is tinted by recovery zone — blue for recovered, amber for recovering, magenta for still stressed. It is informational: it never changes the rest countdown.

GPS and marking a spot

Off by default, and worth leaving off unless you want spots. Always On records the session start, every dive, and any spot you mark. Entry & Exit records only entry and exit, for far less battery. Either mode runs the receiver from the moment you open the app, not just during a session.

Mark Spot — in the end-session menu — saves where you are into inDepth's own log and the watch's saved locations, so Garmin Navigate can steer you back to it later. Pick a label (Reef, Fish, Wreck, Entry, Boat, Hazard); 30 marks per session. GPS does not reach through water, so every position is taken at the surface — mark from directly above the spot, not on the way up.

If you mark your entry point and then decide not to dive, BACK opens the end-session menu rather than discarding — choose Stop & Save to keep the mark. Such a session stays on the watch and is not synced to the phone; the watch's own saved location is written the moment you mark and survives either way, so that is the copy to rely on.

Data

• Capture Garmin FIT Files — off by default. Turn it on if you also want each session to appear in Garmin Connect.
• Store Detailed Stats — on by default (off on the Fenix 5, 5S and 5X). Off means no depth graph and no heart-rate trace; everything else still records and syncs.
• Reset to Factory Settings — erases every setting and your whole on-watch dive history. Exit and reopen the app afterwards.

If something looks wrong

My depth reads far too shallow

Check the table above — on a Fenix 7 or either Descent, Garmin caps the reading at about 3 m. Nothing in the app can lift it.

A deep alarm never fired

On a capped watch it physically cannot, and on any watch a deep alarm is not guaranteed to reach you. Never treat a depth alarm as a safety backstop.

An alarm sounded but no dive was logged

A wave over the watch can read as a couple of metres for a second or two. The detection was discarded as surface noise; the alert had already fired and cannot be taken back.

My depths are all a few percent off

Water type (Fresh / Salt) was probably wrong for that session.

My dive screen counted up and no button worked

Buttons are ignored during a dive on purpose. If the watch's depth readings stop arriving, the dive is force-ended and recorded after 15 minutes — and BACK works as an escape once that point has passed.

Older sessions have disappeared from the watch

The watch keeps the last 10 sessions — 5, and about 25 dives, on a Fenix 5 or 5S — and drops the oldest whether or not it has synced. Sync every few sessions and nothing is lost. On a Fenix 5 or 5S a single session longer than 38 dives is also cut back to its newest 38 the next time the app starts, and the dives past that never reach the phone. After a day that long, sync it before you close the app — end the session, sync while inDepth Blue is still open, then leave.

My watch rebooted after saving a session

Seen on the Descent Mk3i and Fenix 7 — a Connect IQ firmware issue the app now works around. If it happens again, turn on Diagnostic Logging in the hidden DEBUG menu, reproduce it, then sync so the phone can collect the trail and send it to us.

"This build has expired"

Sideloaded Connect IQ apps expire 180 days after the build date. Install a newer build from /install before then.

My Fenix 5 / 5S is missing features I read about here

Those two watches run a reduced build — no spot marking, no per-alarm audio and vibration settings, no stress meter, no session notes, five minutes of dive profile per dive, and the smaller session limits above. Their memory is simply too tight for the rest.