As with tables, there are several rules you must follow when using dive computers. Following these rules helps to ensure their accuracy and your safety.

Dive computers vary in their display, operation, and features. For this reason, you should carefully read the computer's manual before using it for the first time.

Computers feature a decompression mode that displays decompression requirements in the event you exceed your maximum dive time. The fact that this feature exists does not equip you with the skills and equipment required for planned decompression dives. You should use this feature only in the event you accidentally exceed your dive limits.

No two divers share the same dive profile, so each diver must have his or her own computer. Additionally, since the remaining dive time indicated by each computer may be different, you should follow the most conservative limit.