Divers use tables with decompression modes when conducting diving descents. Currently, tables are being replaced by underwater computers, into which modern mathematical models of decompression algorithms are programmed. None of the existing models takes into account the individual characteristics of the organism, the processes occurring in the body under conditions of high pressure of the gas and water environment, and does not describe the real processes well enough. Modern diving computers are able to supply a diver with a large amount of information. Based on data on depth, time, number of dives and time of surface intervals, they help to plan dives, inform when it is necessary to make an ascent, assign, if necessary, safety stops and calculate the time before the flight by plane. Currently, it is safe to say that a computer is simply necessary for a diver. His health, and sometimes his life, depends on it.