Birth of a Sport
The Early Regulators
by Nick Icorn

The first diaphragm operated demand regulator was developed in France by Benoit Rouquayrol, a mining engineer, and August Denayrouse, a naval lieutenant during the period 1863 to 1865.

The unit consisted of a volume tank made of copper, approximately 20 inches long by 10 inches in diameter. This was mounted horizontally across the diver's back. Attached to the top was a single stage, lever operated, demand regulator. On the end of the cylinder a shut off valve connection was provided for attachment of a surface supplied hose.

Working pressure of the cylinder was limited to 250-350 psi at that time, providing only a short duration of air as a back-up if the surface air supply was cut off.

Patents were obtained in 1865 on the entire unit as well as the regulating devices in a single stage and two stage concept. The unit was called the "Aerophore " and saw use by the French Navy for a period of 7 years. In addition, it was introduced to the sponge fishing industry. Later, a rubber suit and full face mask was added to the design for more comfort.

Jules Verne in 1870 equipped his divers in his novel "TWENTY THOUSAND LEAGUES UNDER THE SEA" with the Aerophore apparatus.

In 1875, a triple tank unit was offered, mounted upright on the diver's back with the regulator attached at an angle to prevent hitting the back of the diver's head. This was introduced in the field with a higher pressure air supply allowing more useful time under water.

In 1926, Commander Yves Le Prieur and Maurice Femez developed a hand controlled free flow unit using a 38 cu.ft. 1,800 psi cylinder. In 1927 a full face mask was added by Le Prieur. Classes and demonstrations were conducted in the use of the apparatus in swimming pools and the open ocean.

In December 1942, with the occupation of France, the French Navy became inactive and a young Naval lieutenant found himself pursuing a dream of a completely automatic breathing device. Jacques-Yves Costeau made contact with Air Liquide CIE, the major gas equipment company in Europe. There he was introduced to a young Canadian gas engineer, Emile Gagnan. Together they took an existing butane gas regulating device and reworked it for underwater use. The initial concept had only one hose and a Fernez mouth piece. Unfortunately, it free flowed air in certain position underwater. In February of 1943, the initial two hose regulator concept was born with a flapper type exhaust valve located at the diaphragm level. Later a patent was granted on the two hose concept and exhalation system.

In 1946, La Spirotechnique was formed to produce the first regulators in Europe. The "Aqua-Lung" regulator became a reality.