Garmin Descent Mk3i 51 mm Dive Computer, Black

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Product guide

Garmin Descent Mk3i 51 mm Dive Computer, Black

Black: The Garmin Descent Mk3i is a 51 mm watch-style dive computer for divers who want dedicated dive modes alongside fitness and smartwatch functions. Its 1.4-inch AMOLED display, dive mapping and log tools are paired with SubWave features that require a compatible separately sold transceiver for tank monitoring.

At a glance

Supports multiple dive modes for recreational and technical scuba diving, as well as freediving.
DiveView maps include bathymetric depth contours and more than 4,000 dive sites.
Stores and displays logs for up to 200 dives, with sharing through the Garmin Dive app.
Built-in LED flashlight offers red or white light, variable intensities and strobe modes.
Fitness and wellness tools include heart-rate, sleep and respiration tracking. The maker says the readings are estimates, not medical measurements.

Price

$1,299.99Save 19%

Reference price: ~~$1,599.99~~

Price checked: Nov 14, 2026

View offer

Often bought together

Garmin Descent™ T2 Transceiver, Subwave™ Wireless Communication | Monitor Up to 8 Tanks When Under Water, Pair with Your Compatible Air-Integrated Descent™ Dive Computer (Sold Separately)

$499.99

IPG for Garmin Descent Mk3i (Case Dimention:51 mm) Hydrogel Screen Protector (2 Units) Invisible HD Clear Film Anti Scratch Guard-Smooth/Self-Healing/Bubble for Mk3i/51 mm

$14.95

Pros and cons

Pros

Combines dive-computer functions with sports apps and smartwatch features in a watch-style device.
Dive log capacity of up to 200 dives and mapped dive-site information can support planning and reviewing trips.
The built-in flashlight provides red or white light with adjustable intensity and strobe options.

Cons

Tank-pressure and depth monitoring for a group requires a separately sold Descent T2 transceiver.
GPS tracking does not work underwater, so underwater navigation relies on the listed dive tools and sensors rather than GPS positioning.

Technical specifications

13 specifications

Identity
Brand	Garmin
Model	Descent™ Mk3i – 51 mm

Display and video
Screen size	1.4 inches
Screen technology listed	AMOLED

Connectivity and controls
Wireless connection listed	Bluetooth, USB
Control methods listed	Push Button

Power and battery
Battery life listed	25 days
Battery type	Lithium Polymer

Dimensions and installation
Form factor	Round
Dimensions listed	2.01 x 2.01 x 0.63 inches
Weight listed	105.6 g

Materials and protection
Water resistance listed	Waterproof

Computing specifications
Storage listed	32 GB

What to know before buying

SubWave preset diver-to-diver messages require software v.15.70 or later. Tank-pressure and depth monitoring for up to eight divers requires a Descent T2 transceiver sold separately, and is specified within 10 meters. The listing also describes preset messages up to 30 meters. GPS tracking does not work underwater. Dive readiness and wellness data are estimates, not medical advice, and Pulse Ox availability varies by country.

What’s in the box

Included

Descent Mk3i 51 mm watch with carbon gray DLC titanium and DLC titanium band
Black silicone band
Black extra-long adjustment strap
USB-C to clip charging/data cable
Documentation

Who is it for?

A good fit for

Divers seeking a watch-style computer with multiple dive modes, dive logs and mapped dive sites.
Buyers who also want fitness tracking, sports apps and smartwatch functions outside diving.
Divers who may use SubWave messaging or add a compatible T2 transceiver for group tank monitoring.

Less suited to

Buyers seeking underwater GPS tracking.
Divers who need tank-pressure monitoring included without purchasing a separate transceiver.

Garmin Descent Mk3i 51 mm Dive Computer, Black · photo 2 — Additional product photo 2

Customer reviews on Amazon

4.7 / 5 · 139 ratings

5 stars89%89%
4 stars2%2%
3 stars2%2%
2 stars4%4%
1 star3%3%

Customer feedback describes strong impressions of functionality and performance, praises battery life, and reports mixed experiences with durability, including some concerns about long-term reliability. The listing claims up to 25 days of battery life, but the operating conditions are not specified, so that figure does not establish how long a particular dive configuration will last. The aggregate rating is generally favorable, while ratings alone cannot clarify what drove less favorable experiences.

Positive themes

Customer feedback praises functionality and performance.
Customers report positive impressions of battery life and value.

Mixed feedback

Durability feedback is mixed, with some customers expressing concerns about long-term reliability.

Frequently asked questions

Can the Descent Mk3i track GPS underwater?

No. The listing states that GPS tracking does not work underwater. It lists an underwater compass among the navigation sensors.

Does the Mk3i monitor other divers' tank pressure by itself?

No. Tank-pressure and depth monitoring for up to eight divers requires a Descent T2 transceiver, sold separately. The listing specifies a range of 10 meters for that group monitoring.

What does the 25-day battery claim mean?

The listing gives a battery life of 25 days but does not specify the operating mode or usage conditions for that figure, so treat it as a listed claim rather than a guaranteed runtime.

Is the dive readiness feature a medical assessment?

No. The listing describes its tracked data as close estimates and states that the device is not a medical device.