Porpoise (scuba gear) Porpoise (scuba gear) Porpoise is a tradename for scuba developed by Ted Eldred in Australia and made there from the late 1940s onwards. The first Porpoise was a closed circuit oxygen rebreather, and the following models were all single hose open circuit regulators. This rebreather was developed by Ted Eldred in the late 1940s and early 1950s. Some were made and used for sport diving, but they did not go into full production. It was worn on the back without a casing. The bag was between the canister and valve assembly and the diver's back. It had two wide breathing
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