The Jacques Cousteau Aqualung has been a topic of debate in expert and amateur diving communities for more than fifty years. This self-regulating underwater breathing equipment was first designed by Jacques Cousteau and his partner, French engineer Emile Gagnan, in the winter of 1942-1943, while Cousteau was a French Naval Officer during the 2nd World War. Cousteau and Gagnan patented the technology which was later to become the most widely used diving regulator in the world.
Aqualung’s technology as we know it today was fully developed in the 1960s, when the French oceanographer perfected and used it for diving exploration aboard his vessel, the Calypso. Today, the aqualung is simply known as a common diving regulator or demand valve and is an indispensable part of a diver’s equipment. The early aqualung was based on a patent developed by Benoît Rouquayrol in 1860 and the 1925 compressed air device developed by Captain Yves Le Prieur. Like its predecessor, it was initially intended to help divers breathe more efficiently underwater, but with a clear advantage: the aqualung solved the problem of continuous airflow limiting the amount of time divers could stay submerged. The patent was registered in 1943, and became known as a significant engineering breakthrough.
Further improved after the end of the War by Jacques Cousteau, aqualung devices made it possible for divers to spend more than an hour underwater – a feat impossible with the traditional devices used before 1945. Aqualung devices were much lighter and easier to carry, allowing divers to use more potent tanks able to carry up to 200 atmospheres of pressure. The aqualung became a commercial success, and in 1956 they were the main breathing devices used by divers during the filming of Cousteau’s “The Silent World,” allowing Cousteau and his Divers to explore and film underwater more freely. The task was further made easy by the development of several new types of underwater cameras that Cousteau also had a hand in adapting.
While the original aqualung was an open-circuit design that allowed air to flow directly to the diver from the cylinder, most previous breathing devices were closed-circuit, using a scrubber to remove CO2 and an apparatus that fed the air back to the diver through a loop – also known as a “rebreather” circuit. While rebreathers are still being used today, most open-circuit breathing devices developed in the present are based on the Jacques Cousteau aqualung, including modern SCUBA regulators designed for deep ocean exploration.