DESCRIZIONE
Conventional SCUBA diving equipment is heavy and cumbersome, mainly due to the mass and size of the breathing gas carrier, i.e. the pressure vessel. A preferred pressure vessel for SCUBA diving can be as light as possible and neutrally buoyant at all stages of the dive. To achieve such preferred characteristics, the pressure vessel volume can be adjusted in accordance with the change in its mass. The present invention provides SCUBA systems that provides for the preferred characteristics.