Cousteau, Jacques-Yves, koo stoh, zhahk eev (1910-1997), was a French oceanographer, author, and motion-picture producer. He developed many techniques for undersea exploration. In 1943, Cousteau helped invent the aqualung. This breathing device enables a diver to move about freely under water for long periods. Cousteau also developed the first underwater diving station and an underwater observation vehicle called the diving saucer.