International Scientific Vocabulary bathy- + Greek skaphē light boat
First Known Use: 1947
Navigable diving vessel developed by Auguste Piccard (assisted by his son Jacques), designed to reach great depths in the ocean. 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 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).