The Descent™ X50i dive computer supports four 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 device 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 App).

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 dive computer can only be used in gauge mode for 24 hours.