Deepstar 4000 was a US Navy/Civilian Deep Submergence Vehicle designed by Jacques Cousteau and built by Westinghouse. It was built in 1965 and retired in 1972. On one Deep star 4000 dive its crew narrowly escaped tragedy when the ascent system and its backup failed at 10,000 feet down. To save the craft mercury ballast used for trim was hand pumped onto the ocean floor and the craft could rise. Some of the explorations of Deepstar 4000 were shown in the January 1971 edition of National Geographic. At the time of the article, Deepstar 4000 had already completed more than 200 dives in the Atlantic, Pacific, and Caribbean.