Solo diving II. In the late 1940s, after the invention of the Aqua-lung by Cousteau and Gagnan, the first retail underwater breathing apparatus for sport was commercially marketed. As the sport expanded through the 1950s, several sporting organisations – notably the Young Men's Christian Association (YMCA) – began scuba training programmes for swimming enthusiasts, thus began the codification of what was believed to be proper practices for the expanding amateur sport of scuba diving. The buddy system was thought to be a useful corollary to the "never swim alone" edicts of the YMCA swimming and lifesaving programmes. Cousteau independently implemented a buddy
King of the Coral Sea Rafferty, Charles Tingwell and Lloyd Berrell all knew each other from working in Sydney radio. Also featuring in the cast was Ilma Adey, a model and cabaret entertainer without any previous acting experience, and Frances Chin Soon, a local nurse from Thursday Island. The film was shot almost entirely on location on Thursday Island, except for the underwater footage, which was filmed off Green Island. Noel Monkman was primarily responsible for this. The filming was unique as the cameraman and the actors dived with a rare scuba known as the Lawson Lung. It was a patent violation of the Cousteau-Gagnan