A little history about single-hose regulators
The PURPOISE regulator
Ted Eldred (1920-2005) was an Australian who was recognized as the world's first inventor of the two-stage regulator in 1952.
Development of this technology began in 1949. Ted Eldred's company, Breathing Appliances Pty Ltd, was located in Melbourne, where the first PORPOISE regulators and hookahs were manufactured.
The performance of PORPOISE regulators was superior to that achieved with Aqualung regulators based on Cousteau-Gagnan technology, starting in 1955. This period corresponded to a phase of significant development for Breathing Appliance Co., with the submission of numerous prototypes to the Australian Navy, which far surpassed all attempts made by their competitors, within the framework of global development. Unfortunately, Ted Eldred transferred his patents to Aqualug under the pressure of "commercial intimidation" in 1956.
The CRISTAL regulator
In May 1955, Jean Bronnec from Brittany and Raymond Gauthier from Berry filed a patent for a two-stage hydrant regulator, the fabulous CRISTAL regulator, which would be marketed by their Marseille-based company in partnership with Yves Girault.
In no time, Commander Cousteau sued them, but his claim was dismissed.
This didn't stop Aqualug from releasing its first hydrant regulator in 1957: the Aquamatic, which would be marketed worldwide (e.g., Aqualug/US Diver in the USA, Spirotechnique in France, and Barakuda in Germany).
The AQUAMATIC regulator
