Jacques Cousteau and Pierre-Antoine was released in 1954. During the 1940s, Cousteau is credited with improving the aqua-lung design which gave birth to the open-circuit scuba technology used today. According to his first book, "" (1953), Cousteau started diving with Fernez goggles in 1936, and in 1939 used the self-contained underwater breathing apparatus invented in 1926 by Commander Yves le Prieur. Cousteau was not satisfied with the length of time he could spend underwater with the Le Prieur apparatus so he improved it to extend underwater duration by adding a demand regulator, invented in 1942 by Émile Gagnan. In 1943 Cousteau tried
Aqua Lung/La Spirotechnique Aqua Lung/La Spirotechnique La Spirotechnique (now Aqua Lung International) is a large and well-known firm which makes scuba and other self-contained breathing apparatus, and other diving equipment. It produced the Aqua-Lung line of regulators, like the CG45 (1945) and the Mistral (1955), among others. Until 2016, the company was a division of Air Liquide since its foundation in 1946. The company was sold to Montagu Private Equity in 2016. In December 1942 the "lieutenant de vaisseau" (ship-of-the-Line Lieutenant) Jacques-Yves Cousteau met in Paris for the first time the engineer Émile Gagnan, employee at Air Liquide, a French company specialising in