1957–1958 – RV "Vityaz" –– In August 1957, the 3,248-ton Vernadsky Institute of Geochemistry research vessel "Vityaz" recorded a maximum depth of ± at in the western basin of the Challenger Deep during a brief transit of the area on Cruise #25. She returned in 1958, Cruise #27, to conduct a detailed single beam bathymetry survey involving over a dozen transects of the Deep, with extensive examination of the western basin and a quick peek into the eastern basin. Fisher records a total of three "Vityaz" sounding locations on Fig.2 "Trenches" (1963), one within yards of the 142°11.5' E location, and a third at , all with ± depth. The depths were considered statistical outliers, and a depth greater than 11,000 m has never been proven. Taira reports that if "Vityaz" depth was corrected with the same methodology used by the Japanese RV "Hakuho Maru" expedition of December 1992, it would be presented as ±, as opposed to modern depths from multibeam echosounder systems greater than with the NOAA accepted maximum of ± in the western basin.