Descent Mk3 Series - Recent Threads

Alert display

6709852 — Sat, 18 Apr 2026 06:05:05 GMT

Hello everybody,

I very often get an alert at the wrong time for example: Approaching deco stop, high PPO2, suggested gas switch, ascending too fast …

When I get this alert, the first thing I want to check immediately is my depth and it is masked by the message. Some messages (gas switch) even require multiple steps for acknowledgement and you do not always have immediately both hands available.

I think the worst one is the gas switch request because nobody would accept to switch gas without checking once more the depth which you can’t do because it is hidden.

Would it be possible on the MK3i not to have all alert/message in full screen ?

FW 25.21

Adam-1972 — Thu, 16 Apr 2026 15:57:13 GMT

Hi.
I just got firmware v25.21 but as I see nothing on the forum here about new version (Descent MK3i).
Anyone have idea what it might be?

Regards.

Sudden reboot during activty - Again, and again and again!

5833674 — Wed, 15 Apr 2026 10:17:32 GMT

Last night, for the umpteenth time, a sudden reboot occurred during a swimming activity. This has happened so often now, and despite various updates, the issue remains unresolved. If you look around in the forum, there are always reports of unexpected reboots during activities. I'm really getting fed up with this unreliable device! Sure, the activity was saved, but it contains almost no useful data—distance covered: 0 meters in nearly 90 minutes? And this is a watch marketed as a dive computer. I no longer have any confidence that this won't happen suddenly while underwater. Is there no quality control in place before a software release?

Descent Mk3/Mk3i System Software 25.21

Garmin-Jimmy — Tue, 14 Apr 2026 19:18:16 GMT

Hello Descent Mk3 users,

We made a minor change to this update and are now rolling out System Software 25.21, this update has been 100% released.

Change Log:

Adds Dive Setup Sharing - the ability to copy your gas list, conservatism, and more to another Garmin computer.
[Mk3i Only] Adds Sidemount support - Get a notification when the pressure difference between two of your tanks differs.
[Mk3i Only] Adds RTR datafield - Show the air time remaining in the lower of two sidemount tanks.
[Mk3i Only] Improves connection stability with the Descent S1 buoy.
Improves behavior of the GF99 datafield on the surface.
[Mk3i Only] Fixed ending tank pressures in the dive log potentially showing an incorrect value.

New MK3i launched

ghabbe — Tue, 14 Apr 2026 12:49:51 GMT

What's new on this watch? www.garmin.com/.../

MK3i Wont start up

4287816 — Wed, 01 Apr 2026 05:15:14 GMT

Mk3i Started with some touch screen issues, now the watch is completely dead. Does not start up.

Have tried:

1. new cable

2. left it to charge for 30mins +

3. force reboot (holding top left button for 30-60 seconds)

4. Connected to Mac - the device doesn't get detected.

The watch wont start up or show any signs. What other options i have?

Terrible at stroke counting

DM — Tue, 31 Mar 2026 15:11:03 GMT

Hello everyone.

Want to share my experienca of swimming with Mk3i (43mm).

Can anyone explain how does it count strokes quantity? Or maybe I have one unique defective device?

1) I was counting my strokes during freestyle and made 18 (few times 17 or 19) strokes per 25 m pool many times in a row during a distace of 500-1500 m for many trainings. Device showed that I made 9-12-8-9-14-7-13... and so on. Yes, I know, that it counts only half of strokes (BTW anyone knows WHY!?), but what kind of formula should we use to get 18-18-18-18-18-18 (which is for some unknown reason is 9-9-9-9-9-9) out of 9-12-8-9--14-7-13??

2) Situation gets much worse when I need my *** strokes count - this is when watches go completely insane. I swim breaststroke trying to relax and make as less strokes as possible per 25m pool. Here are the numbers that I actually counted: 6-7-6-6-6-6 strokes per pool. And here is the device stroke count (correctly recognizing stroke type): 9-14-16-12-14-12. Is my device broken??

And one more funny situation. When I decided to swim veeery slowly making even less *** strokes and did 5 strokes per pool at 150 m distance, my watches refused to count swimming at all! It showed that I swim 0 meters!

As I said, device recognizes stroke type correctly almost all the time. Also, it counts number of pools (distance) very good - no worries about that. But what's wrong with stroke numbers? Do other people have the same issues?

Heart rate data not displaying correctly

2748000 — Sun, 29 Mar 2026 10:35:37 GMT

Hi All,

I’m running into an issue with heart rate data not displaying correctly after SCUBA dives and would appreciate any help.

Setup:

Watch: Garmin Descent Mk3i
Chest strap: Garmin HRM-Pro Plus
Diving with a drysuit (strap stays dry and records throughout the dive - fwiw it's been exposed to 11atm and works fine)

Process:

Complete the dive
Sync HR data from the chest strap to the watch
Sync the watch with the Garmin Connect & Dive (IOS) apps

Issue:

In the Dive app, the heart rate chart only shows data for the last ~2 minutes of the dive
However, when the same activity is viewed by my Girlfriend via her own (Android) Garmin Connect app (e.g. by a connection), the full heart rate data (chart) for the entire dive is visible. Important to note: my girlfriend can see two entries for the same dive; one entry is identical to mine and it has only a couple of minutes of heart rate data in the graph, and the other has the full heart rate data.

So it seems the data is recorded correctly, but not displayed properly in my Dive (IOS) app. All apps are fully updated.

Screenshot of the Garmin Dive app (IOS) on my own phone with missing data:

Screenshot from my girlfriend's Garmin Connect app showing the full data:

Thank you for taking the time!

Question for garmin mk3i (iPhone) users

5049597 — Mon, 23 Mar 2026 10:52:03 GMT

Hey folks,

I currently run an AWU2 and love it, I’ve run AW’s daily since year dot and I find it perfect for my recreational diving so far.

I am however torn and have been toying with the idea of AI so looking at the mk3i (51mm) and happy with all the activity features etc. the battery life is also a big draw.

But trawling through all the reviews and videos it’s hard to see how it performs as an actual smart watch…

So existing users, how are the notifications? Can you interact with them, read and reply to texts, iMessages and WhatsApp etc?

Any other thoughts on the mk3i v the AWU2 that aren’t dive related?

Thanks all.

a722db290c704534becf492b06541889 — Fri, 20 Mar 2026 09:23:25 GMT

Is WhatsApp coming? On mk3i

Descent Mk3i 51 mm sleep tracking issue after firmware 25.14 update

visitor29 — Mon, 09 Mar 2026 17:40:24 GMT

I am using a Garmin Descent Mk3i 51 mm. Since updating to firmware 25.14 six days ago, my watch has stopped detecting and recording sleep properly.
The problem started immediately after the update. Since then, the watch has not been automatically triggering sleep and my sleep has not been recorded correctly.
I also tried reinstalling the firmware, but that did not help. The issue is still present.
Before this update, sleep tracking was working normally, so this appears to be related to firmware 25.14.

Descent Mk3/Mk3i System Software 25.14

Garmin-Jimmy — Tue, 03 Mar 2026 16:33:11 GMT

Hello Descent Mk3 users,

We have started the rollout of System Software 25.14, currently we are at 20% with this rollout and we will increase the % as time goes by.

Major Changes since 23.49 (last public release)

Fixed shading of DiveView map bathymetry contour lines
Fixed an issue that could cause a dive computer error when switching to an oxygen diluent in a CCR dive.
Fixed an issue where dives in pool mode would increase the total dive count
Fixed some S1 buoy strings being cut off in certain languages
Fixed inconsistency with recovery time in Dive Readiness widget

System software 25.14

FIREDEX — Tue, 03 Mar 2026 16:26:35 GMT

Hi, just received update to 25.14. Any changlog available? Seems it's stuck on the 23.49

“Back” button cap fell off and it is lost. Any place to buy new cap ?

1672220 — Tue, 03 Mar 2026 03:00:40 GMT

Somehow cap is unscrewed and fell off. It happened once before but felt in my hand. I screw it back as tight as possible but now it is lost? Any place on the earth is possible to buy one ?

Cheers

T2 transmitter does not read the correct tank pressure even after replacing the battery.

2604514 — Sat, 28 Feb 2026 18:44:15 GMT

Descent T2 Transceiver does not read the correct tank pressure even after replacing the battery. Testing my tank outside the water prior to my next dive.

Drag Screen Down Does Not Work

4328150 — Wed, 25 Feb 2026 03:29:01 GMT

I have a Garmin Mk3i 43mm and for the last few months I have not been able to drag the screen down as I previously could. As far as I can tell, the Touch is set to On in the Garmin Connect app. I have restarted the watch a couple of times and still nothing. My husband has the Mk2 and it works for him. Not sure why it stopped working for me.

Current Software Version: 23.49

Phone: Samsung S25 Ultra

My Mk3i (23.49 software) has developed a touch screen issue.

dougmack — Fri, 20 Feb 2026 14:00:45 GMT

My Mk3i (23.49 software) has developed a touch screen issue. When touch is enabled the watch frequently cycles through random screens. I've noticed that apps have been deleted, reorganised, etc because of touch being activated. The watch was being worn but the screen was not being touched by hand or clothing. With touch disabled the watch behaves normally. I've rebooted the watch but the same issue occurs.

Has anyone else experienced this?

Feature Request: Auto Lock timeout setting

2226172 — Sun, 08 Feb 2026 22:27:30 GMT

Hello Garmin Devs!

I would like to request the addition of an Auto Lock timeout setting, as it would be nice to change the default Auto Lock timeout (10 seconds) to something else eg. {10s, 30s, 1 minute}.

I know that it's possible to set a hot key for locking/unlocking, but I do appreciate the Auto Lock feature and it would be nice to have a timeout setting for it.

Thanks!

Missing data fields on Stock Watch Faces - Descent Mk3i (51mm) - Firmware 23.49

9693588 — Thu, 22 Jan 2026 20:30:06 GMT

Hi everyone,

I’m reaching out to report an issue with the watch face on my Descent Mk3i 51mm running firmware version 23.49.

Recently, I’ve noticed that several data fields have stopped displaying information. Specifically:

Step Counter: When I select it, the field remains completely blank/empty.

Other Data Fields: Multiple other data points are no longer visible, leaving empty spaces where the icons or numbers should be.

Note: I am using official stock Garmin watch faces, not third-party ones from Connect IQ. The issue persists even if I try to customize or switch between different pre-installed watch faces.

I have already tried to restart the device, but the problem remains. Is anyone else experiencing this with the 23.49 build?

Thanks in advance for your help!

Heart rate graph not responding as surface data field during spearfishing activity

Dan86 — Mon, 12 Jan 2026 20:35:38 GMT

Dear Garmin,

I have contacted the support center without resolving the issue, so I am reporting it here once more. During certain activities such as spearfishing and freediving, even when I select the "heart rate graph" as data in the surface screen, it fails to appear, and only a black screen with void data is shown on the designated page. This is quite frustrating, especially since several updates have been released (including the most recent one from last week), and it appears that Garmin has chosen not to address this matter, despite the fact that we are discussing a premium series watch.

What is the faint background image when I look at my favorite activities? It doesn't show when I scroll down to other activities.

3290741 — Thu, 01 Jan 2026 04:13:06 GMT

What is the faint background image when I look at my favorite activities? It doesn't show when I scroll down to other activities.

Dropped MK3i 51mm

7671249 — Mon, 29 Dec 2025 05:45:14 GMT

Dropped mk3i 51mm from bed onto concrete floor, about 1.5ft (half a meter) high. Other than some minor scratches on the bezel, I did not see any visible sign of damage on the watch.

How likely is the drop going to affect the diving function. Would be a great help if someone could share their experience if they had a similar drop.

I wonder if there are any needs to test the watch's diving function as a safety precaution prior to actual dives? If yes, how do I test it? Can it be an at-home test or it needs to go to Garmin?

Problem: Decent Mk3i losing connection to T2 under water after 23.49 update, only came back after leaving water

7527495 — Tue, 16 Dec 2025 18:46:37 GMT

During the first dive after the 23.49 update the Mk3i lost connection to the T2 transmitter and only got it back exactly when leaving the water.

So I was diving an hour "air blind". Good that I know that my consumption is much better than my buddy's, so I relied on that.

Very unpleasant experience.

Dive data screens - number of fields/layout should be customisable

5853917 — Sun, 14 Dec 2025 17:06:01 GMT

Anyone else feel like the diving data screens should have ability to customise the layout and quantity of data fields from the default?

For example, on the 51mm mk3i, the second data screen onwards have 5 customisable fields (3 fields on the 43mm sizes), but we are not able to reduce the number of customisable fields shown if we do not require all 5 fields. This leads to unnecessary visual clutter and the reduced size of data fields. Custom data screens should follow similarly to other activity profiles where we can adjust the quantity and layout of fields. For clarity, the 3 essential fields on the bottom (dive depth, time, and NDL), these should stay as-is.

Also, the top-most custom data field should have more contextual info - for example when set to HR it should also display the heart symbol instead of just a number, and when set to temperature it should also show the temperature unit (C/F), not just the degree symbol, which might be confused with a compass heading at a glance. This is how the Fenix 8 displays data during a dive, and I'm surprised the descent series is lagging behind on this aspect.

Descent Mk3i System Software 23.49

Garmin-Jimmy — Thu, 11 Dec 2025 22:23:17 GMT

Hello Descent Mk3i users,

Today we started the rollout of System Software version 23.49 is now fully rolled out.

Change Log:

(Mk3i Only) Improved how quickly the device reconnects to SubWave transmitters while underwater.
(Mk3i Only) Fixed an issue where removing an S1 buoy could remove other Wi-Fi networks too.
Fixed several issues with the inReach remote, especially when paired with newer inReach devices.
Fixed being unable to access inReach SOS pages while the device is passcode-locked.
(Mk3/Mk3i Only) Fixed being unable to use the Kill Switch hot key while the device is passcode-locked.
Fixed an issue causing the Apnea screen to update less frequently than it should.
Fixed a potential stability issue with ANT connections.
Fixed "open connection" showing for HR broadcast every time instead of just the first.
Fixed being unable to set an NDL AWARE field via Garmin Dive/Garmin Connect.

Descent Mk3 Series - Recent Threads

Alert display

FW 25.21

Sudden reboot during activty - Again, and again and again!

Descent Mk3/Mk3i System Software 25.21

New MK3i launched

MK3i Wont start up

Terrible at stroke counting

Heart rate data not displaying correctly

Question for garmin mk3i (iPhone) users

Whatsapp

Descent Mk3i 51 mm sleep tracking issue after firmware 25.14 update

Descent Mk3/Mk3i System Software 25.14

System software 25.14

“Back” button cap fell off and it is lost. Any place to buy new cap ?

T2 transmitter does not read the correct tank pressure even after replacing the battery.

Drag Screen Down Does Not Work

My Mk3i (23.49 software) has developed a touch screen issue.

Feature Request: Auto Lock timeout setting

Missing data fields on Stock Watch Faces - Descent Mk3i (51mm) - Firmware 23.49

Heart rate graph not responding as surface data field during spearfishing activity

What is the faint background image when I look at my favorite activities? It doesn't show when I scroll down to other activities.

Dropped MK3i 51mm

Problem: Decent Mk3i losing connection to T2 under water after 23.49 update, only came back after leaving water

Dive data screens - number of fields/layout should be customisable

Descent Mk3i System Software 23.49