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 Jacques Cousteau Jacques-Yves Cousteau (; 11 June 1910 – 25 June 1997) was a French naval officer, explorer, conservationist, filmmaker, innovator, scientist, photographer, author and researcher who studied the sea and all forms of life in water. He co-developed the Aqua-lung, pioneered marine conservation and was a member of the Académie française. Cousteau described his underwater world research in a series of books, perhaps the most successful being his first book, "", published in 1953. Cousteau also directed films, most notably the documentary adaptation of the book, "The Silent World", which won a Palme d'or at the 1956 Cannes Film