Garmin has started rolling out software version 28.04 to the Descent Mk3, Mk3i and Mk3s, and unlike the string of Fenix updates that shipped with nothing but "miscellaneous bug fixes," this one actually says what changed.
The release is going out in stages and is currently reaching roughly 20 percent of active devices. If your Mk3 has not offered it yet, that is the phased rollout rather than a problem with your watch.
The dive alarm logic got smarter
The headline change is in how the watch handles ascent rate alarms, and it is a fix aimed at divers who got tired of being shouted at.
Under the new logic, the alarm only fires if you ascend faster than 30 feet (10 meters) per minute for 10 consecutive seconds, or faster than 60 feet (20 meters) per minute for 5 seconds. Previously the threshold crossed more easily, which meant nuisance alerts on otherwise controlled ascents.
Anyone who has had a watch chirp at them while doing a deliberate, controlled ascent knows why this matters. An alarm that cries wolf is an alarm you learn to ignore, and an ignored ascent alarm is worse than no alarm at all.
There is a second, more technical change for closed circuit rebreather divers. The watch no longer factors upcoming automatic setpoint switches into its Time-To-Surface calculation. Garmin made that change to bring the Descent Mk3 line in line with how the rest of the dive industry computes TTS.
Maps and a genuinely strange location bug
Several mapping issues are fixed in 28.04:
- Dive site icons can now be toggled on or off directly in the map view, which matters when a busy area turns into a mess of pins.
- A bug that blocked adding dive sites to saved courses is resolved.
- A location bug that occasionally logged random entry and exit coordinates is fixed. Affected logs had dives placed in the wrong spot, frequently somewhere near the coast of Africa, which is a long way from most people's local quarry.
- Secondary dive modes can no longer trigger accidentally while you are in Pool Apnea mode.
That Africa coordinate bug is the kind of thing that seems trivial until you realize it means the entry point on your dive log is fiction. For anyone who uses the log to plan repeat dives or track a site over seasons, wrong coordinates make the log actively misleading.
The Pool Apnea fix matters for a narrower group, mostly pool training and freediving work, where the last thing you want is the watch dropping into a different dive mode mid-session.
Setup Sharing gets an explanation
Garmin also added an explanatory page for the Setup Sharing feature. That screen now walks you through exactly which settings and data transfer when you set up a new watch, which answers a question people have been asking since the feature arrived.
It is a small addition, but this is the sort of feature people avoid out of uncertainty about what it will overwrite.
How to get it
The update is deploying automatically in stages. To pull it manually:
- Open the main menu on the watch.
- Go to Settings, then System, then Software Update.
- Select Check For Updates while connected over Wi-Fi or Bluetooth.
The Descent G2 got the same 28.04 version a few days earlier, on November 5, so this is the Descent line updating as a family rather than the Mk3 alone. We covered the G2 when it launched, and the 51mm Mk3i is the newest member of this family.
Bottom Line
If you dive with a Descent Mk3, Mk3i or Mk3s, install 28.04 when it appears. The ascent alarm rework is the change you will actually notice, because it turns a feature you had probably started ignoring back into one worth listening to.
The map and coordinate fixes are the ones that quietly matter more over time. A dive computer is only as useful as the log it keeps, and the Descent Mk3 just stopped corrupting that log.
Sources: Garmin News on the 28.04 release, Garmin Rumors' software update tracker.
