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 also lived there. Jacques-Yves Cousteau and Marcel Ichac shared the same desire to reveal to the general public unknown and inaccessible places — for Cousteau the underwater world and for Ichac the high mountains. The two neighbors took the first ex-aequo prize of the Congress of Documentary Film in 1943, for the first French underwater film: "Par dix-huit mètres de fond" ("18 meters deep"), made without breathing apparatus the previous year in the Embiez islands (Var) with Philippe Tailliez and Frédéric Dumas, using a depth-pressure-proof camera case developed by mechanical engineer Léon Vèche (engineer of Arts and Métiers and the