Garmin has added a new size option to its Descent Mk3i lineup. The 51mm version with silver and black titanium build gives divers who want more screen real estate an option that matches the feature set of the existing 43mm model.
This is a size expansion, not a new product. The Descent Mk3i already existed, and now there is simply a larger case option for those who prefer it. The specs are identical between sizes.
The headline feature is the 1.4-inch AMOLED display covered by sapphire crystal. That is a meaningful step up from smaller dive watches and makes it easier to read data at depth or on the surface. The screen is bright and clear, which matters when dealing with varying light conditions underwater.
This thing is built for serious diving. It is rated at 20 ATM, which means it can handle dives up to 200 meters. If you are a technical diver or spend a lot of time in the water, that kind of rating matters.
Battery life is where this really stands out. You get up to 66 hours in dive mode, which is the number that matters for serious divers. If you use it as a daily smartwatch, you can stretch that to about 25 days with regular settings, though the always-on display will cut that down to around 10 days.
One of the most useful features is SubWave sonar support. This lets you send preset messages underwater to other divers using compatible devices, with a range of up to 30 meters. When paired with the Descent T2 transceiver, the watch can track tank pressure and depth for up to eight divers within 10 meters of each other. That is a solid safety feature for group dives.
Garmin loaded this with multiple dive modes covering single and multi-gas setups, including Nitrox and Trimix. It also supports freediving, apnea, gauge mode, and closed-circuit rebreather diving. The built-in DiveView maps show depth contours for more than 4,000 dive sites, which helps with planning and navigation.
There is also a focus on overall health and readiness. The watch can estimate your dive readiness based on sleep, stress, and activity levels. Beyond diving, you get a dive compass, surface GPS tracking, a variometer, and real-time no-decompression limit data.
Outside the water, this works like a full smartwatch. It has more than 80 sports apps, heart rate tracking, VO2 max, Pulse Ox, sleep tracking, and training suggestions. You also get music storage, contactless payments, and notifications. There is 32 GB of onboard storage.
The price is $1,599.99, identical to what the 43mm model costs.
For divers who preferred the smaller Descent Mk3i but wanted a larger display, this 51mm version delivers exactly that. It is a solid option if smaller watches felt too cramped on your wrist but you still want all the dive features Garmin offers.