Classification of the underwater diving equipment

In this paper was presented, innovative in preparation of the diving apparatuses classification method, depend on three criteria: the kind of the breathing gas, the operational depth range of the diving apparatus, and the principle of operation. The breathing gas used is the most important criterion. The other basic classification criteria follow from the first one; therefore it should be treated as the one criterion. Such approach to the problem has never been presented before, however it seems to be correct method of the diving apparatuses division.