The Descent™ Mk2i device supports six dive modes. Each dive mode has four phases: dive pre-check, surface display, in-dive, and post-dive. During the pre-dive check, you can confirm the dive settings before you start diving (Dive Setup). The surface phase shows the data screens for the dive mode ( Dive Data Screens). The in-dive phase shows data about the dive in progress, and other watch features, such as GPS, are disabled (Going Diving). During the post-dive review, you can view a summary of the completed dive (Viewing the Dive Log Widget).

Single-Gas

This mode allows you to dive with a single gas blend. You can set up to 11 additional gases as backup gases.

Multi-Gas

This mode allows you to configure multiple gas blends and switch gases during your dive. You can set the oxygen content from 5–100%. This mode supports one bottom gas, and up to 11 additional gases as decompression or backup gases.

NOTE: Backup gases are not used in no-decompression limit (NDL) and time to surface (TTS) decompression calculations until you activate them during a dive.

CCR

This mode for closed-circuit rebreather (CCR) diving allows you to configure two partial pressure of oxygen (PO2) setpoints, closed-circuit (CC) diluent gases, and open-circuit (OC) decompression and backup gases.

Gauge

This mode allows you to dive with basic bottom timer features.

NOTE: After diving in gauge mode, the device can only be used in gauge or apnea mode for 24 hours.

Apnea

This mode allows you to free dive with apnea-specific dive data. This mode has a higher data refresh rate.

Apnea Hunt

This mode is similar to the Apnea dive mode, but tuned specifically for spearfishers. This mode disables start and stop tones.