The first single hose SCUBA was made by Ted Eldred in Melbourne, Australia. Ted told me he sold his first on early in 1952. It was called the CA-1 (CA was for compressed Air, 1 was for the single tank) Ted had been making oxygen rebreathers and realized air was a better option.
This picture is of the CA-1 with it's wrap around canvas harness. The wrap allowed the diver to dump the heavy 2800 psi German 50 cu ft tank by pulling a release pin. Prior to this tank, a short low pressure tank was used, but they were WWII surplus and soon ran out.
The Porpoise that was sold in 1952 looked like the one in this leaflet and had a web strap harness made like a basket.
The Porpoise regulator came in it's own box. The box held two spanners for fitting and adjusting first stage settings. The box had a nose clip and a glass depth gauge and an instruction book.
Ted Eldred said he was pressured to sell out to Aqua Lung under a threat that they would flood the market with cheap overseas gear. Ted sold in 1960 and was out of diving by 1962. The Historical Diving Society SEAP honored him three years running, until he passed away.
This picture was taken at the site of his first SCUBA school in Melbourne. He was 82 and teaching his grandson Adam, how to dive the Porpoise he invented.
The two cylinder Porpoise CA-2 is the rarest of the Porpoise models. Only two are known to exist. This one is complete with the original cylinders and valves dated 1953. It was purchased by the original owner, from the inventor and sold to me 53 years later. The chromed reduction valve cap had to be replaced by the inventor when it came off during a dive. An un-chromed one was located in the factory and installed, making it even more rare.