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 out the first prototype aqua-lung which finally made extended underwater exploration possible. In 1946, Cousteau and Tailliez showed the film "Épaves" ("Shipwrecks") to Admiral Lemonnier, who gave them the responsibility of setting up the Groupement de Recherches Sous-marines (GRS) (Underwater Research Group) of the French Navy in Toulon. A little later it became the GERS (Groupe d'Études et de Recherches Sous-Marines, = Underwater Studies and Research Group), then the COMISMER ("COMmandement des Interventions Sous la MER", = "Undersea Interventions Command"), and finally more recently the CEPHISMER. In 1947, Chief Petty Officer Maurice Fargues became the first diver to die using