Stranger crossed the center basin twice, measuring a maximum depth of 10,830 metres (35,530 ft) ±20 m (66 ft) in the vicinity of 142°22’E. At the western end of the central basin (approximately 142°18’E), they recorded a depth of 10,805 metres (35,449 ft) ±20 m (66 ft).[31][failed verification] The western basin received four transects by Stranger, recording depths of 10,830 metres (35,530 ft) ±20 m (66 ft) toward the central basin, near where Trieste dove in 1960 (vicinity 11°18.5′N 142°15.5′E﻿ / ﻿11.3083°N 142.2583°E﻿ / 11.3083; 142.2583, and where Challenger II, in 1950, recorded 10,863 metres (35,640 ft) ±35 m (115 ft). At the far western end of the western basin (about 142°11’E), the Stranger recorded 10,850 metres (35,600 ft) ±20 m (66 ft), some 6 km south of the location where Vityaz recorded 11,034 metres (36,201 ft) ±50 m (164 ft) in 1957–1958. Fisher stated: "…differences in the Vitiaz (sic) and Stranger–Challenger II depths can be attributed to the [sound] velocity correction function used…"[29] After investigating the Challenger Deep, Stranger proceeded to the Philippine Trench and transected the trench over twenty times in August 1959, finding a maximum depth of 10,030 metres (32,910 ft) ±10 m (33 ft), and thus established that the Challenger Deep was about 800 metres (2,600 ft) deeper than the Philippine Trench.[32] The 1959 Stranger surveys of the Challenger Deep and of the Philippine Trench informed the U.S. Navy as to the appropriate site for Trieste's record dive in 1960.[33]