Dive computer
A dive computer, personal decompression computer or decompression meter is a device used by an underwater diver to measure the elapsed time and depth during a dive and use this data to calculate and display an ascent profile which, according to the programmed decompression algorithm, will give a low risk of decompression sickness. Most dive computers use real-time ambient pressure input to a decompression algorithm to indicate the remaining time to the no-stop limit, and after that has passed, the minimum decompression required to surface with an acceptable risk of decompression sickness. Several algorithms have been used, and various personal conservatism factors may be available. Some dive computers allow for gas switching during the dive. Audible alarms may be available to warn the diver when exceeding the no-stop limit, the maximum operating depth for the gas mixture, the recommended ascent rate or other limit beyond which risk increases significantly. The display provides data to allow the diver to avoid decompression, or to decompress relatively safely, and includes depth and duration of the dive. Several additional functions and displays may be available for interest and convenience, such as water temperature and compass direction, and it may be possible to download the