Scuba computers, or dive computers, are compact digital devices which perform the task of nitrogen management without the need for a watch or dive tables. Combining a timer with a depth gauge, and intelligent software which computes absorption of gases, dive computers are popular with experienced recreational divers. While it is essential that all divers learn about residual nitrogen and decompression using manual dive tables, a computer is a valuable device that enhances your dive experience by automating nitrogen management.stops, if necessary.
A dive computer does not plan a dive for the scuba diver. A scuba diver is still responsible for planning a dive safely in accordance with health guidelines. What the computer does is: keep track of depth and time spent underwater, computes the amount of nitrogen present in the diver’s body, alerts the diver of levels getting too high and guides the diver to make appropriate decompression
On a traditional manual dive table there are only 2 variables used to describe a dive: maximum depth and time. The calculation of absorbed nitrogen assumes that the diver plunged immediately to maximum depth, stayed there for a duration and then bobbed back up to the surface. Then the dive profileis “square” – if it is graphed on an X-Y grid it would look like a rectangular trench. In practice a dive is never like that: a diver will descend slowly, swim around and up and down, change depth to navigate reefs or bottom formations and then slowly ascend to the surface.
The most enticing advantage of a dive computer is longer bottom times. Dive tables with a square profile are necessarily conservative; the exaggerated absorption on the safe side. The accurate curved profile of computerized depth tracking invariably allows the diver to stay down deeper, longer.
Here are some things to consider when choosing a dive computer:
- Research the dive computer’s brand and model. Look for recognizable manufacturers and consult consumer guides.
- Is it easy to change the battery without dissembling the unit?
- Is the dive computer’s interface intuitive, easy to read and backlit?
- Some dive computers can upload your dive data to a PC for use in scuba planning and logging software. Not all dive computers have this feature. Do you want this feature?
- Will the dive computer handle gas mixes other than air, such as nitrox?
- Does the dive computer support decompression management and a “time-to-fly” feature?
- Does the dive computer use a well-tested algorithm for calculating gas absorption and decompression? For example, the Mares-Wienke Reduced Gradient Bubble Model (RGBM) Algorithm and the Buhlmann algorithm, etc.
- Are the buttons large, spaced far apart and easy to press while wearing neoprene gloves?