The Calypso was built in the USA in 1942 as a minesweeper. She was bought in 1950 by Jacques-Yves Cousteau, and after extensive changes and modifications, has become a fully equipped ocean research vessel, complete with an observation chamber in the stern, an oval diving bell, a Galaezzi diving chamber, an inflatable boat for shallow waters, a helicopter and much other submarine equipment. Length: 42 m, tonnage: 360 tons, speed: 12 knots.