Thomas Washington returned briefly to the Challenger Deep on 17–19 October 1978 during Mariana Expedition Leg 5 under chief scientist James W. Hawkins.[48] The ship tracked to the south and west of the eastern basin, and recorded depths between 5,093 metres (16,709 ft) to 7,182 metres (23,563 ft). Another miss. On Mariana Expedition Leg 8, under chief scientist Yayanos, Thomas Washington was again involved, from 12–21 December 1978, with an intensive biological study of the western and central basins of the Challenger Deep.[49] Fourteen traps and pressure-retaining traps were put down to depths ranging from 10,455 metres (34,301 ft) to 10,927 metres (35,850 ft) meters, the greatest depth was at 11°20.0′N 142°11.8′E﻿ / ﻿11.3333°N 142.1967°E﻿ / 11.3333; 142.1967.