SCUBA

Self-contained Underwater Breathing Apparatus (as opposed to diving equipment supplied with air from the surface).

Term normally applied to diving equipment that supplies air from a tank by means of a demand (suction operated) valve.

Invented in practical form in the 1940s by Jacques Cousteau and Emile Gagan. Cousteau originally dubbed the device an "Aqualung"; but the British Navy decided that this sounded like an unpleasant disease, and insisted on renaming it "SCUBA".