Dive computer

Dive computer

Hydrospace Explorer Trimix and rebreather dive computer. Suunto Mosquito with aftermarket strap and iDive DAN recreational dive computers
Other names	Personal dive computer
Uses	Dive profile recording and real-time decompression information

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.^[1][2] A secondary function is to record the dive profile, warn the diver when certain events occur, and provide useful information about the environment.

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, and some monitor the pressure remaining in the scuba cylinders. 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, decompression ceiling, 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. This must be displayed clearly, legibly, and unambiguously at all light levels. 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 data from the dives to a personal computer via cable or wireless connection. Data recorded by a dive computer may be of great value to the investigators in a diving accident, and may allow the cause of an accident to be discovered.

Dive computers may be wrist-mounted or fitted to a console with the submersible pressure gauge. A dive computer is perceived by recreational scuba divers and service providers to be one of the most important items of safety equipment.^[3] It is one of the most expensive pieces of diving equipment owned by most divers. Use by professional scuba divers is also common, but use by surface-supplied divers is less widespread, as the diver's depth is monitored at the surface by pneumofathometer and decompression is controlled by the diving supervisor. Some freedivers use another type of dive computer to record their dive profiles and give them useful information which can make their dives safer and more efficient, and some computers can provide both functions, but require the user to select which function is required.