Editing Challenger Deep (section)

===1988 – RV ''Moana Wave''===
On 22 August 1988, the U.S. Navy-owned 1,000-ton research vessel ''Moana Wave'' (AGOR-22), operated by the Hawaii Institute of Geophysics (HIG), [[University of Hawaii]], under the direction of chief scientist [[Robert Thunell|Robert C. Thunell]] from the [[University of South Carolina]], transited northwesterly across the central basin of the Challenger Deep, conducting a single-beam bathymetry track by their 3.5&nbsp;kHz narrow (30-degs) beam echosounder with a Precision Depth Recorder. In addition to sonar bathymetry, they took 44 [[gravity core]]s and 21 [[box core]]s of bottom sediments. The deepest echosoundings recorded were {{convert|10,656|to(-)|10,916|m|ft}}, with the greatest depth at 11°22′N 142°25′E in the central basin.<ref>Physical and Chemical Data, RISEPAC Expedition 7–23 December 1961; Proa Expedition 12 April – 6 July 1962; and Zephyrus Expedition 12 July – 26 September 1962; SIO Reference 66-16</ref> This was the first indication that all three basins contained depths in excess of {{convert|10,900|m|ft}}.

[[File:Hakuho Maru, Fremantle, 2019 (06).jpg|thumb|The RV ''Hakuhō Maru'']]