Garmin Descent Mk3i (Black, 51mm)

How does the SubWave sonar technology work underwater?

SubWave sonar technology uses sound waves to transmit preset messages between divers up to 30 meters apart underwater. The system requires software version 15.70 or later and works by converting digital messages into acoustic signals that travel through water. When paired with the Descent T2 transceiver, it can monitor tank pressures and depth data for up to eight divers within a 10-meter range, providing real-time group diving information.

What dive modes are supported by the Mk3i?

The device supports multiple dive modes covering recreational scuba diving, technical diving and freediving. Recreational modes include standard air and nitrox diving with decompression calculations. Technical modes support trimix, CCR (closed-circuit rebreather) and multi-gas diving with advanced decompression algorithms. Freediving modes track depth, time and surface intervals with specific safety features for breath-hold diving activities.

How long does the battery last during diving activities?

The Mk3i offers up to 25 days of battery life in smartwatch mode. During diving activities, battery consumption increases due to the active display, sensors and SubWave sonar operations. Typical dive computer usage provides several days of diving before requiring a charge. The device includes a USB-C charging cable and can be charged between dive sessions to maintain full functionality.

Is the titanium construction worth the extra cost?

The 51mm titanium bezel and optional titanium band provide superior corrosion resistance compared to stainless steel, particularly important for saltwater diving. Titanium is significantly lighter than steel whilst maintaining strength, reducing wrist fatigue during extended wear. The material also offers better biocompatibility for people with metal sensitivities and maintains its appearance longer in harsh marine environments.

Can I use this watch for surface sports and fitness tracking?

Yes, the Mk3i functions as a complete multisport GPS smartwatch with built-in sports applications for running, cycling, swimming and other activities. It includes GPS tracking, heart rate monitoring and performance metrics. The device also supports Garmin Pay for contactless payments, music storage for wireless headphones and smart notifications when paired with a compatible smartphone.

What comes included in the box?

The package includes the Mk3i watch with carbon grey DLC titanium case, a black silicone diving band, a black extra-long adjustment strap for use over wetsuits and a USB-C charging cable with clip connector. The titanium bracelet is sold separately. Documentation includes quick start guides and safety information for diving computer operation.

How accurate is the dive readiness assessment feature?

The dive readiness tool analyses data from sleep tracking, stress monitoring, exercise history and travel patterns to provide an estimation of physical preparedness for diving. Garmin states this data is intended as a close estimation rather than medical advice. The feature helps identify when factors like poor sleep or high stress might affect diving safety, but should not replace proper dive training and personal assessment.

Do I need additional equipment to use all the diving features?

The basic dive computer functions work independently without additional equipment. However, to access tank pressure monitoring and extended SubWave sonar features, you need to purchase the Descent T2 transceiver separately. This device attaches to your regulator's high-pressure port and communicates wirelessly with the watch to provide air supply information and enhanced diver-to-diver communication capabilities.