The Descent™ X50i dive computer supports multiple 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). You can also verify the connection to your paired Descent accessories. 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: No-decompression limit (NDL) and time to surface (TTS) decompression calculations include the use of bottom gas and decompression gas. Backup gases are not used in NDL and TTS 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.