One of the early, recreational scuba diving pioneers, Commandant Yves Le Prieur – the French Navy Commander who designed the single lens mask for use in submarine escape – had, in 1934, devised and patented a self-contained underwater breathing apparatus (SCUBA) consisting of a cylinder of compressed air slung on the chest with a rubber tube leading to a full-face mask.
Lacking a regulator, the diver hand-valved air into the mask as required.
The text accompanying the image – one that appears in a later edition of Guy Gilpatric’s classic 1934 book, ‘The Compleat Goggler’ – states:
“Commandant Le Prieur, wearing his self-contained diving gear, demonstrates his Nautilus gun. The cylinder contains a half-hour’s supply of compressed air. With this simple apparatus, the inventor and many others dive for sport, science and salvage.
Actually, the apparatus is worn with bathing trunks, but when Commandant Le Prieur came out of the water to pose for this picture, it started to rain; so he put his clothes on.”