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
Submarine Products Submarine Products Submarine Products Ltd (1959−1990) was a diving gear manufacturer, with a factory in Hexham in Northumberland, England. It was founded in 1959 by Lt.Cdr. Hugh Oswell. Until the late 1950s, the British Siebe Gorman company patents kept aqualungs expensive in Britain, and many British sport divers had to use home-made breathing sets and ex-armed forces or ex-industry rebreathers. Some became expert at home-making scuba diving demand regulators from industrial parts such as Calor Gas regulators. In 1959 Hugh Oswell designed around the Cousteau-Gagnan patent and made sport diving breathing sets accessibly inexpensive. Submarine Products Ltd were the first