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 Island Jacques Cousteau Island Isla Cerralvo (), as is commonly named, whose official name is Isla Jacques Cousteau (; ), is an island located off the Cerralvo Canal coast near La Paz, Baja California Sur, Mexico. It is long with a land area of , and is the ninth-largest island in Mexico. It is part of Municipality of La Paz. The island peak comes to and the ridge line runs north-south with many small streams draining east to Gulf of California and west to Cupalo Canal. There are many steep bluffs on the eastern sides and many sandy beaches and points