Air tank adapter for converting a self-contained breathing apparatus to a self-contained underwater breathing apparatus

A new and improved air tank adaptor for allowing a self-contained air breathing apparatus (SCBA) air tank to be used as a self-contained underwater breathing apparatus (SCUBA) air tank, said air tank adaptor comprising:

• a yoke adapter to which a conventional first stage SCUBA air pressure regulator may be attached to receive air from a conventional SCBA air tank;
• said yoke adapter comprising a block member having at least first, second and third sides;
• said first side of said block member having a first conical indent;
• said second side of said block member having a threaded receptacle;
• said third side of said block member having a second conical indent larger than said first conical indent whereby said conventional first stage SCUBA air pressure regulator may be attached to said first and second conical indents of said block member;
• a conduit in said block member extending between said second conical indent in said second side of said block member and said threaded receptacle in said second side of said block member;
• and
• coupling means attachable to said block member between said threaded receptacle and the outlet of said conventional SCBA air tank.