History of scuba diving the high number of recreational scuba accidents. this started with informal training and led to the creation of training and certification agencies. BS-AC was formed in 1953, CMAS in 1959, NAUI in 1960 and PADI in 1966. The sport of scuba diving had its roots among the multitude of small enthusiastic snorkelling and spearfishing clubs in the decades just before and after the Second World War. After the invention of the "aqualung" by Cousteau and Gagnan, the first commercially marketed underwater breathing apparatus became available for sale for sporting purposes in the late 1940s. In 1951, Jim Auxie Jr and
Aqua-Lung than its precursor, which in fact was almost completely unknown outside France. In addition, and most importantly, the Aqua-Lung could be mounted on stronger and reliable air tanks holding up to 200 atmospheres, allowing extension of diving duration to more than an hour at significant depths (including the needed time for decompression stops). The first Cousteau-Gagnan Aqua-Lungs (like the CG45 of 1945 or the Mistral of 1955) were mainly twin-hose open-circuit scuba. They have since been made by various manufacturers with varying design details and numbers of cylinders. Like modern open-circuit scuba with single-hose regulators, they consisted of one or