Garmin Descent Mk2i Review: The Dive Computer for Divers Who Do Everything

The short version

The Descent Mk2i is the dive computer for people whose watch never comes off. It is a genuinely excellent multisport GPS smartwatch that also happens to be a full technical dive computer — Bühlmann ZHL-16C with gradient factors, six dive modes including nitrox, trimix and CCR, a 3-axis compass, and a 100 m rating. Independent testers rated it best in class for readability in sunlight and for easy, intuitive operation, which is not a small thing on a computer this feature-dense.

The honest catch: air integration is where the complaints live. The T1 transmitter is sold separately at around $400 — making the practical buy-in roughly $1,850 — and it has a documented history of reading tank pressure low and occasionally dropping signal mid-dive. Garmin support replaces faulty units readily under warranty, but you should know this going in.

Who it's for: divers who also run, ride, swim, and travel, and want one premium device for all of it.

Who should skip it: new or occasional divers — it's overkill, and a fraction of the price buys excellent dedicated dive computers.

What owners consistently praise

• • Readability. Test labs called the display excellent in direct sunlight, and owners agree; with the backlight on it stays legible in dark water.
• • Operation. Reviewers scored it top of its class for intuitive operation and ergonomics — a four-button layout that stays usable in gloves, plus a touch screen and a shake-to-change-screen gesture that work in dive mode.
• • The everyday watch case. This is the part competitors can't match: owners describe it as a phenomenal adventure watch that they wear every day between trips. Nothing from the dedicated dive brands comes close as a daily driver.
• • Battery. About 16 days as a smartwatch, 80 hours in dive mode (about 32 with the transmitter connected) — owners report "a good week" of mixed use. Heavy GPS use is the exception: expect roughly 2 days, worth planning around on expedition trips.
• • Durability. Owners with a year-plus on the watch report the sapphire glass shrugs off scratches and units still look near-new after several years of active use.
• • Deco behavior. A multi-day owner comparison found its NDL tracking in line with a Shearwater Perdix and Teric across a week of diving.

The problems, plainly

• • The T1 transmitter is the weak link. The recurring, multi-source complaint — concentrated around the 2021–22 T1 launch — is tank pressure reading low, often not fixed by firmware and ultimately resolved by warranty replacement. Signal drops mid-dive also come up; owners work around them by setting transmit power to high and keeping line-of-sight placement. Whatever computer you dive, keep an analog SPG as backup — with a flaky transmitter it's non-negotiable.
• • SubWave is also the T1's redemption. The sonar-based link genuinely works underwater in ways radio can't, and can show a buddy's tank pressure (up to five transmitters) — a feature owners really do use.
• • It's big. 52 mm of watch. Reviewers flag it as bulky for everyday wear, especially on smaller wrists.
• • Sealed battery, proprietary charger. The main battery is not user-replaceable (end-of-life means device replacement through Garmin), and the charging clip is proprietary — some owners report contact corrosion after salt exposure, so rinse well. The T1's CR123A, at least, is user-swappable. One firmware update (v12.30) regressed battery life for some owners before later fixes.
• • The gauge-mode trap. After a gauge-mode dive the computer locks itself to gauge/apnea for 24 hours. It's documented, deliberate behavior — and a genuine gotcha that can sideline the deco features for a day of a trip if you trigger it by accident.
• • Servicing is mail-in. Local dive shops can't service it; it goes back to Garmin. The upside: forum reports consistently describe support replacing faulty units without a fight, and we found no recalls or safety notices in the manufacturer sources we checked.

Where it sits in 2026

The Mk2i is now the prior-generation flagship — the Mk3i and AMOLED Descent X sit above it in Garmin's lineup — which softens its value at full price but makes it a strong buy on discount. Current price and availability are in the live table above.

Alternatives worth cross-shopping

• • Garmin Descent G1 — same algorithm in a budget body, no air integration. The pick if you want Garmin fitness features without flagship money.
• • Shearwater Peregrine — the recreational benchmark: superb screen, user-replaceable battery, no AI or smartwatch anything. See our [Peregrine vs Perdix 2 comparison](/gear/guides/shearwater-peregrine-vs-perdix-2).
• • Shearwater Peregrine TX — the Peregrine plus air integration; the most direct "just a dive computer" rival to an AI-equipped Mk2i.
• • Suunto Ocean — the premium AMOLED smartwatch-diver alternative.

For the wider field, our [Best Dive Computers 2026](/gear/guides/best-dive-computers) guide covers every budget.

Bottom line

Buy the Mk2i if the "one watch for everything" pitch describes your life — nothing else does that job this well, and the dive side is legitimate. Budget for the T1 with eyes open about its track record, dive with an SPG backup, and if you only ever dive, buy a Shearwater and pocket the difference.