Method of detecting the beginning of a dive for a dive computer

This invention provides in the dive computer-type portable electronic device (1) performed on a test dive start method. This method has at least one of the first operating mode, and a second mode of operation called the dive mode type device implementation. The appliances include is used to measure the surrounding pressure value (p) pressure transducer (5) referred to in for processing and measuring electronic circuits on the results of (2), which includes time base (4) and at least one store (7,8). According to the measurement of the invention according to the ambient temperature (p) to provide benchmark measurements of the pressure value (Pref) updates the value used to test dive start. Under certain conditions, according to the method of the present invention to suspect diving begins, in this case, will be stored before the Update baseline pressure value (Pref) backup (Psauv). If you have doubts it is found that the dive began, after you activate the dive mode, the reference pressure value stored (Pref) was backed up value (Psauv) instead.