From 20 to 30 November 1980, Thomas Washington was on site at the western basin of the Challenger Deep, as part of Rama Expedition Leg 7, again with chief-scientist Dr. A.A. Yayanos.[1] Yayanos directed Thomas Washington in arguably the most extensive and wide-ranging of all single-beam bathymetric examinations of the Challenger Deep ever undertaken, with dozens of transits of the western basin, and ranging far into the backarc of the Challenger Deep (northward), with significant excursions into the Pacific Plate (southward) and along the trench axis to the east.[2] They hauled eight dredges in the western basin to depths ranging from 10,015 metres (32,858 ft) to 10,900 metres (35,800 ft); and between hauls, cast thirteen free vertical traps. The dredging and traps were for biological investigation of the bottom. In the first successful retrieval of a live animal from the Challenger Deep, on 21 November 1980 in the western basin at 11°18.7′N 142°11.6′E﻿ / ﻿11.3117°N 142.1933°E﻿ / 11.3117; 142.1933, Yayanos recovered a live amphipod from about 10,900 meters depth with a pressurized trap.[3] Once again, other than a brief look into the eastern basin, all bathymetric and biological investigations were into the western basin.[4]