Depending on the gases used, the level of qualification of the supervisors and the skills of the divers, the diving areas are defined as follows:
0 to 6 metres;
0 to 12 metres;
0 to 20 metres;
0 to 40 metres;
0 to 60 metres;
Space from 0 to 70 metres;
Space from 0 to 80 metres;
Spaces above 80 metres.
Underwater diving with air is limited to 60 metres.
Underwater diving with trimix or heliox mixes is limited to 80 metres.
Autonomous underwater diving with trimix or heliox mixes is limited to 120 metres.
The oxygen content of the nitrox determines the breathing space.