Navigable diving vessel developed by
The first bathyscaphe, the FNRS 2 , was built in 1946–48 in Belgium. A later version, the Trieste , was acquired by the U.S. Navy; in 1960 it dived to a record 35,810 ft (10,916 m) in the {{link=Mariana Trench">Mariana Trench . The bathyscaphe consists of two main components: a steel cabin, heavier than water and resistant to sea pressure, to accommodate the observers; and a light container called a float, filled with gasoline, which, being lighter than water, provides the necessary lifting power (replacing cables, which had previously been used to support descending chambers but had proven unreliable at great depths).