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
Céline Cousteau ocean explorer and shark advocate, and granddaughter of Jacques Yves Cousteau. She grew up between their family homes in France and the United States, and as the granddaughter of legendary explorer and oceanographer Jacques Cousteau, Celine spent much of her youth aboard his famous research vessel "Calypso", plying the seas in search of answers to the oceans' greatest mysteries. One of her first major expeditions was at age nine when she journeyed to the Amazon with her family. There they spent 18 months navigating its waters in areas that were still largely unknown to the outside world. It was on