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
Christian J. Lambertsen Breathing Apparatus). Although diving regulator technology was invented by Émile Gagnan and Jacques-Yves Cousteau in 1943 and wasn't originally related to rebreathers, the current use of the word SCUBA is largely attributed to Gagnan's and Cousteau's invention. The US Navy considers Lambertsen to be "the father of the Frogmen". Lambertsen was born in Westfield, New Jersey and attended Rutgers University in New Brunswick, New Jersey, graduating in 1939 with a bachelor of science degree. He graduated from medical school at University of Pennsylvania, Philadelphia, Pennsylvania in 1943. Lambertsen was awarded Honorary Doctor of Science Degree from Northwestern University in 1977.