Dive computer

Dive Computers

Scuba diving computers allow divers to extend their bottom time and increase their safety underwater, here is a selection of leading dive computers from manufacturers such as Suunto, Uwatec and other leading diving equipment manufacturers.

A dive computer or decompression meter is a device used by a scuba diver to measure the time and depth of a dive so that a safe ascent rate can be calculated and displayed so that the diver can avoid decompression sickness.

Dive computers address the same problem as decompression tables, but are able to perform a continuous calculation of the partial pressure of inert gases in the body based on the actual depth and time profile of the diver. As the dive computer automatically measures depth and time, it reduces the need for the diver to carry a separate watch and depth gauge and is able to warn of excessive ascent rates and missed decompression stops. Many dive computers also provide additional information to the diver, for example, the water temperature, information on the diver's oxygen toxicity or the pressure of the remaining breathing gas in the diving cylinder.


Because of the computer's ability to continually re-calculate based on changing data, the diver can gain the ability to safely remain underwater for longer periods of time using an equal volume of gas. For example, a recreational diver who plans to stay within "no-decompression" limits can simply ascend a few feet at a time (while continuing the dive) in order to remain within safe limits, rather than adhering to a pre-planned bottom time and ascending directly. So-called multi-level dives can be planned with traditional dive tables, but the additional calculations become complex and the plan may be cumbersome to follow. Computers allow for a certain amount of spontaneity during the dive.


The first mechanical analogue dive computer, the decompression meter was marketed by Scubapro in 1972. It was very simple in principle: a waterproof bladder filled with gas inside a big casing bled into a smaller chamber through a calibrated porous ceramic cartridge (to simulate tissue in/out gassing), whose pressure was measured by a manometer whose graduation indicated decompression stops. The device was eventually nicknamed bend-O-meter.
Several analogue decompression meters were subsequently, some with several bladders for illustrating the effect on various body tissues, but they were sidelined with the arrival on the scene of electronic computers.
Early examples of recreational diving digital, electronic computers, from 1979, are the Hans Hass DecoBrain and Orca Edge.


Dive computers provide a variety of visual dive information to the diver.
Modern dive computers display the following information on a LCD:
Current depth.

Maximum depth reached on this dive.

No stop time, the time remaining at the current depth without the need for decompression stops.

Dive time, often measured from the end of the last longer surface interval.

Many dive computers also display additional information:

Required decompression stop depth and time.

Water temperature.

Ascent rate.

Dive profile (often not displayed during the dive, but transmitted to a personal computer).
Some computers are designed to display information from a diving cylinder pressure sensor, such as:
Gas pressure.

Estimated remaining time based on available gas and rate of gas consumption.

Some information is only shown at the surface to avoid an information overload of the diver during the dive:
"Time to Fly" display showing when the diver can safely board an airplane.

A log of key information about previous dives.

Maximum non-decompression bottom times for subsequent dives based on the partial pressure of the gases in the tissue.