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Jacques-Yves Cousteau

1910 – 1997
French Marine Explorer
Exploration Ranking 16th of 26

Cousteau on a French stamp from 2000.

Nearly three quarters of the surface of the Earth is covered by water. For centuries, people dove for precious underwater products such as pearls and natural sponges. But until the twentieth century, very little exploration was made beneath the seas. This was because breathing apparatus were not available. Without such devices, divers could only stay below the water for as long as they could hold their breath. After inventing an underwater breathing apparatus, Cousteau opened up the undersea world to people across the globe through numerous television series and books. Overall, Cousteau did more than anyone else in history to introduce the underwater world to the general public.


Inventing the Aqualung


In 1943, Jacques-Yves Cousteau designed the first aqualung with Emile Gagnan and Frederic Dumas. An officer in French naval intelligence, Cousteau began working on free-diving equipment in 1936, experimenting with existing systems that used compressed air. The problem with compressed-air tanks for diving use was that they could not dispense the air at the changing pressures of various depths in water. Pressure increases about the equivalent of 1 atmosphere every 33 feet.


After several near-fatal accidents, Cousteau identified the pressure problem and took it to Gagnan, an industrial gas equipment designer. Working with specifications developed by Cousteau, Gagnan developed a valve that linked the diver’s exhaust breath with his intake breath. The outgoing breath opened an outlet valve and at the same time shut off the input air. When the diver breathed in, the outside pressure of the water would close the outlet valve and switch on the incoming air supply from the compressed air tank. A diaphragm kept the pressure equal to the outside water pressure.


The whole unit, including the control valve, the face mask, and the compressed-air tank, was known as the aqualung. In the United States it was called S.C.U.B.A--self-contained underwater breathing apparatus. Today it is commonly referred to as a diving regulator or demand valve. Cousteau successfully dived for the first time with the system in June 1943, reaching a depth of about 60 feet. Aqualung dives were generally limited to about 300 feet until the introduction of a helium-oxygen mixture, using the same valve system. With the removal of the nitrogen in regular air, the aqualung became capable of supporting divers safely to about 400 feet. In the postwar years, Cousteau used the revenue from the aqualung to support research and film voyages of the exploration ship Calypso and became known to television viewers all over the world with his popularization of undersea exploration.


This invention opened a new period of underwater exploration, and with its help, many amazing discoveries have been made. Divers no longer needed to wear heavy protective suits and air cables. They were free to swim around and study underwater archaeology. They could photograph marine life and also search for deposits of oil, diamonds, tin and other minerals. By the 1950s and 1960s, the use of the aqualung for diving became a popular sport. At the same time, many navies adopted aqualung equipment for special missions such as planting mines, intelligence-gathering and for more routine tasks such as maintenance of underwater equipment. Cousteau also developed a process for filming underwater, which revealed to the general public a vast new world beneath the ocean waves.



Over the years, as Cousteau learned more about the water environments around the world, he was one of the first people to promote marine conservation. Later, he started an environmental protection foundation, that today has about 300,000 members. He wrote more than fifty books and produced more than 120 television documentaries on many ocean sites and various major world rivers and lakes, that people around the world read and watched. His work permitted many people to explore the resources of the oceans. Cousteau’s work also created a new kind of scientific communication, criticized at the time by some academics. The so-called “divulgationism,” a simple way of sharing scientific concepts, was soon employed in other disciplines and became one of the most important characteristics of modern television broadcasting.  


Key References


(All by Cousteau)



1. The Silent World, 1956.

2. The Golden Fish, 1959.

3. The World Without Sun, 1965.


Television series

1. 1966-68, The World of Jacques-Yves Cousteau.

2. 1968-76, The Undersea World of Jacques Cousteau.

3. 1977-81, Cousteau’s Odyssey Series.

4. 1982-84, Cousteau’s Amazon Series.

5. 1985-91, Cousteau’s Rediscovery of the World I.

6. 1992-94, Cousteau’s Rediscovery of the World II.



1. Par 18 metres de fond (Through 18 Meters of Water), 1946.

2. The Silent World, 1953.

3. The Living Sea, 1963.

4. Three Adventures: Galapagos, Titicaca, The Blue Holes, 1973.

5. Dolphins, 1975.

6. The Ocean World of Jacques Cousteau – 21 volumes, 1973-78.

7. Jacques Cousteau: The Ocean World, 1985.

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