He was admitted to the �cole Navale (Naval Academy) in Brest and became a gunnery officer of the French Navy, which gave him the opportunity to make his first underwater experiments. In 1936 he tested a model of underwater eyeglasses, perhaps the ancestors of modern masks.
Married in 1937 to Simone Melchior, he took part in WWII as a spy and during the conflict he found the time to be co-inventor, with Emile Gagnan, of SCUBA diving equipment ("aqualung") in 1943.
In the post-WWII years, still a naval officer, he developed techniques for the minesweeping of France's harbors and explored shipwrecks.
Named the president of the French Oceanographic Campaigns, in 1950 he bought his famous ship Calypso, with which he visited the most interesting waters of the planet, including some rivers. During these trips he produced many books and films, one of which won the top award at the Cannes Film Festival in 1956. These works did a great deal to popularize knowledge of underwater biology.
In 1963 with Jean de Wouters Cousteau developed the an underwater camera named "Calypso-Phot" which was later licensed to Nikon and became the "Calypso-Nikkor" and then the "Nikonos".
Together with Jean Mollard he created the SP-350, an two-man submarine that could reach a depth of 350m below the ocean's surface. The successful experiment was soon repeated in 1965 with two vehicles that reached 500m.
Cousteau was made director of the Oceanographic Museum of Monaco, created the Underseas Research Group in Toulon, was the leader of the Conshelf Saturation Dive Program (long-term immersion experiments, the first manned undersea colonies) and was one of the few foreigners that has been admitted to the American Academy of Sciences.
Cousteau's popularity was increasing. In October 1960, a large amount of radioactive waste was going to be discarded in the sea by EURATOM. Le Commandant organized a publicity campaign which gained wide popular support. The train carrying the waste was stopped by women and children sitting on the railway, and was sent back to its origin. The risk was avoided.
In Monaco, the following November, an official visit by the French president Charles De Gaulle turned into a debate on the events of October 1960 and on nuclear experiments in general. The French ambassador already had suggested that Prince Rainier avoid the subject, but the president (allegedly) asked Cousteau in a friendly manner to be kind toward nuclear researchers, and Le Commandant (allegedly) replied: "No sir, it is your researchers that ought to be kind toward us." During this discussion Cousteau found out that the reason for French experiments and research was American refusal to share its atomic secrets with its allies.
In 1974 he created the Cousteau Society for the protection of ocean life, which now has more than 300,000 members.
In 1977, together with Peter Scott, he received the UN international environment prize, and a few years later he also received the American Liberty Medal from Jimmy Carter, then president of the United States.
In 1992 he was invited to Rio de Janeiro (Brazil) for the United Nations' international conference on environment and development, then he became a regular consultant the UN and the World Bank.
Cousteau liked to call himself an "oceanographic technician". He was in reality a sophisticated lover of nature, especially that of the sea. His work allowed people of all continents to visit life under the ocean's surface and explore through television the resources of the "blue continent".
The works that Cousteau produced also created a new kind of scientific communication that caused some criticism by formal academics. The so-called divulgationisme, a simple comprehensible form of sharing scientific concepts, was soon used for other disciplines too and became one of the most important and appreciated characteristics of modern TV broadcasting. The documentary information found in Cousteau's words a linear scheme to follow.
Now Cousteau's figure is admired, beloved worldwide through the many who love the sea, and is regarded to with a sort of devotion, as symbolic of adventure, nature and exploration.
Jacques Cousteau died on June 25, 1997 and is buried in the Cousteau family plot at Saint-Andr�-de-Cubzac Cemetery, Saint-Andr�-de-Cubzac, France.
See also: Scuba diving