Lesson 1, Topic 1
In Progress

Dive Computers

The dive computer, in essence, is a diving table, with a built-in stopwatch and profundimeter. The big difference from the simple dive table is that the computer handles in real time the data collected during the dive and the results are immediately visible on the display.

This allows the diver to make the point of the situation at any time to take the point of the dive situation, while the tables present a fixed results scale.

More recently, through a high-pressure connection from the 1st floor of the regulator (hose or radio emitter), several computer models treat data relating to the air pressure in the bottle, calculating the air consumption at each moment and estimating the duration of the air reserve.

In this way the diver is informed of the dive time he still has without having to perform decompression stops, what levels and decompression times he may have to respect, the speed of climbing he is practicing, the surface intervals, and many more information.

In cases where the dive starts deep and then gradually climbs along a wall, for example, the use of the computer can optimize the time of the dive. In fact, the decompression that is slowly being made as the diver goes up, is a factor continuously calculated and updated by the computer. With a table, such a procedure is impossible.

Upon arrival on the surface, the computer continues to keep the diver informed of how decompression is taking place, thus allowing easy planning of a second dive.

It even allows the correction of the atmospheric pressure to be made in relation to the altitude at which the dive is to take place. In memory are also recorded some data related to dives made, which in the latest generation of computers can be transferred to a desktop computer, in the form of a table or chart.

Currently there are dive computers that have integrated compass and thermometer, in addition to having the possibility to manage dives where different respiratory mixtures of atmospheric air are used.

However, the use of computers does not exclude the use of tables , since these devices are also likely to suffer malfunctions, although they are not very frequent. For safety reasons, even with a computer, the diver must always be accompanied by the table (preferably based on the mathematical model used by the computer) and the means necessary for measuring time and depth (clock and profundimeter).

On the other hand, it is necessary not to forget that there are models of programmed computers with different mathematical models. Thus, in a group of divers where there are different computers, it is very likely that the information obtained does not coincide with each other.

Finally, it should be in mind that it is not the computer that prevents decompression accidents, but the way in which the device is used . The diver must be able to read correctly and without a doubt the data that the device provides on the dial and respect them scrupulously.

Safety rules that apply to the use of tables (do not stretch the times to the limit and respect the safety stop) should also be applied to computer diving. According to Dr. B├╝hlmann, “100% safety can only be achieved by restricting all underwater activities to bath diving.”


  • Never compare the values of the computer and those shown in the dive table.
  • Use either your computer or dive table. Never mix the two.
  • Every diver must have his computer. Two divers always have different dive profiles.
  • If you don’t use a computer and you’re diving with a companion who uses it, never evolve to a depth greater than the one where it’s evolving.
  • Always read the instruction manual carefully before using your computer. Each computer model has its own characteristics.