Jacques-Yves Cousteau is perhaps the most well-known modern scuba diver and undersea explorer. He brought the world of undersea diving within the capabilities of ordinary people by inventing (with Emile Gagnan) the aqualung in 1942. This self-contained underwater breathing apparatus (SCUBA) now enables divers to remain under water for an hour or more instead of minutes. Also, Cousteau helped design other diving equipment such as the two-person diving saucer. His explorations, conducted from his famous oceanic ship Calypso, were documented and earned him numerous honors and awards. Cousteau was born in 1910 in St. Andre-de-Cubzak, France. He attended the Brest Naval Academy and became a naval gunnery officer in 1933. At the age of 47, Cousteau retired from the navy with the rank of corvette captain.

During World War II Cousteau co-invented the aqualung, a device that provides pressurized air to the diver while underwater. Before the aqualung, divers had to wear...