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
Ted Eldred was protected by US patent and international patents, so Eldred set about designing the Porpoise CA (a prototype), the world's first single hose regulator. Eldred referred to the French model as the Gagnan Aqua Lung, as designer Émile Gagnan was the Frenchman who actually designed the device for Jacques-Yves Cousteau. This new design was superior to the Aqua Lung, and did not violate any of the existing patents. Eldred's regulator was never patented as his business was too small for the expense. The first production model was designated the CA-1. (C A for compressed Air, 1 for single cylinder) He