Solo diving II. In the late 1940s, after the invention of the Aqua-lung by Cousteau and Gagnan, the first retail underwater breathing apparatus for sport was commercially marketed. As the sport expanded through the 1950s, several sporting organisations – notably the Young Men's Christian Association (YMCA) – began scuba training programmes for swimming enthusiasts, thus began the codification of what was believed to be proper practices for the expanding amateur sport of scuba diving. The buddy system was thought to be a useful corollary to the "never swim alone" edicts of the YMCA swimming and lifesaving programmes. Cousteau independently implemented a buddy
Jacques Cousteau center of the strait, and the porpoises followed for a few minutes, then diverged toward mid-channel again. It was evident that they knew where the optimal course lay, even if the humans did not. Cousteau concluded that the cetaceans had something like sonar, which was a relatively new feature on submarines. In 1954, Cousteau conducted a survey of Abu Dhabi waters on behalf of British Petroleum. Among those accompanying him was Louis Malle who made a black-and-white film of the expedition for the company. Cousteau won the Palme d'Or at the Cannes Film Festival in 1956 for "The Silent World"