The Autonomous Diving Suit

The "heavy-footers" remained permanently linked to the surface to allow the diver to breathe. However, studies on decompression and the technical possibilities of compressed air reservoirs opened up new avenues for inventors in the nineteenth century: the development of a system that allows man to move about independently under water.

In 1828, an inceptive invention by Lemaire d'Angerville consisted of a leather bag that was placed against the diver's chest.

However, it was only in 1865 when the device of Rouquayrol et Denayrouze, after some perfecting, allowed a diver to swim completely independently underwater for half an hour, at a depth of ten meters. The pressure of the compressed air in the reservoir is automatically adjusted by a rubber membrane which takes on the water pressure.

Nevertheless, one has to wait until the mid-twentieth century until the diver can truly move about without constraint, thanks to the autonomous diving suit with pressure regulator.
In fact, the invention of Rouquayrol and Denayrouze did not have the expected success, and dives would for a long time be conducted using heavy and restrictive equipment.

In 1926, Commandant Le Prieur developed a suit similar to that of Lemaire d'Angerville, with a reservoir with manually controlled airflow which was quite delicate.

Diving outfit - 1950
Musée de la marine

The Cousteau-Gagnan diving suit, 1943

It was only in 1943 that the encounter between Commander Jacques-Yves Cousteau and the engineer Emile Gagnan finally made a century-old dream come true: the first automatic autonomous diving suit, equipped with pressure regulator and compressed air bottles, gave the diver complete independence of movement.

This invention, which was marketed in 1946, swiftly became very successful. For archeologists, the dream to visit undersea sites became reality. In 1952, Commander Cousteau paved the way for this on the site of the Grand-Congloué shipwreck at Marseilles.