Buddy diving just before and after the Second World War. After the invention of the "aqualung" by Cousteau and Gagnan, the first commercially underwater breathing apparatus became available for sale for sporting purposes in the late 1940s. As the new sport of scuba diving rapidly expanded through the 1950s, several sporting organisations—notably the YMCA—began programmes to train swimming enthusiasts in this new aquatic pastime, and began to codify what they believed were proper practises for this expanding sport. The YMCA considered the buddy system a useful corollary to the "never swim alone" rule of their swimming and lifesaving programmes. Cousteau himself independently
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