Open circuit divers should look for a nitrox-compatible dive computer. Overall, a dive computer at minimum should include the following functions.
- No-decompression-time and recognized-decompression algorithms
- Max depth and actual depth
- Altitude compensation
- Nitrox for open circuit diving
- PC or PDA interface
- Automatic freshwater/seawater adjustment or most conservative setting
- Rapid ascent warning
- Required safety stops (if any)
- Required decompression time (if any)
- Surface interval
- Profile storage
- Various warnings: rapid ascent, required safety stop, or decompression violation, etc.
- Battery state of charge
- System status indication
The most important information is displayed, and the other information is in the background for use if needed.