Current status of closed circuit underwater breathing apparatus

Closed circuit diving systems are certainly not a new concept, but advanced technology is turning the concept into practical reality. For years the development of these systems has stagnated in their classified covert operations role, but a new group of sophisticated divers--scientists, photographers and technical divers--has emerged to spur the commercial development of closed circuit underwater breathing apparatus. The traditional silent and bubble-free capability is being augmented with such additions as microprocessor usage, dependable oxygen sensing, carbon dioxide sensing, and PC integration.