Basic Functions of a Dive Computer
The most basic dive computer measures depth, tank pressure, ambient water temperature, and time. The information is displayed to the diver using a waterproof and pressure resistant liquid crystal display or LCD. The functions of the computer are controlled by specially designed microprocessor and customized diving algorithms.
The primary function of a dive computer is to automatically calculate your diving profile to prevent decompression sickness. As any diver who has passed the basic PADI certification knows, you can do this planning yourself using a pen and paper with the diving tables. As a matter of fact you should continue to use the manual methods to plan your dives as a backup even if you dive with a computer.
The advantage of the dive computer is that it takes your real-time depth into account and allows you to plan a dive with either no or minimal decompression stops. The dive computer also allows you more bottom time since the calculations are based upon the actual time you spend at depth.
Another advantage of a scuba diving computer is that they remember your previous dives, and take that bottom time in to account for future dives. By basing the calculations on actual data, you end up spending more time on the bottom during your vacation. Diving computers work by using a mathematical algorithm to estimate how much nitrogen has been absorbed in your body's tissues.
Diving computers can also give you the audible alarms when you ascend to quickly, miss a decompression stop, or are running low on air. Another nice function is the ability to record data, such as maximum depth and reached. Many of the more modern computers can upload your dive profiles directly to your own personal computer.
Finally, a good dive computer will run the timer countdown for how long you should wait until you fly or travel the higher elevations, at least 12 hours but most likely 24 or even 48 hours. While modern dive computers make diving easier and more pleasant, you should ensure you are familiar with all of the functions and displays of your computer before a dive. Also make sure that you have a backup manually prepared diving profile; it's often easier to plan your dives so no decompression stops are required, that way if you have a failure you can safely ascend without worrying about decompression stops.
