Editing Challenger Deep (section)

===1996 – RV ''Yokosuka''===
For most of 1995 and into 1996, the [[Japan Agency for Marine-Earth Science and Technology]] (JAMSTEC) employed the 4,439-ton Research Vessel ''Yokosuka'' to conduct the testing and workup of the 11,000-meter remotely-operated vehicle (ROV) ''[[Kaikō ROV|Kaikō]]'', and the 6,500 meter ROV ''Shinkai.'' It was not until February 1996, during ''Yokosuka''{{'s}} cruise Y96-06, that ''Kaikō'' was ready for its first full depth dives. On this cruise, JAMSTEC established an area of the Challenger Deep (11°10'N to 11°30'N, by 141°50'E to 143°00'E{{snd}}which later was recognized as containing three separate pools/basins en echelon, each with depths in excess of {{convert|10900|m|0|abbr=on}}) toward which JAMSTEC expeditions would concentrate their investigations for the next two decades.<ref>Kairei Cruise Report KR-08-05, p. 8</ref><ref>Kairei Cruise Report KR-14-01, p. 5</ref> The Yokosuka employed a 151-beam SeaBeam 2112 12&nbsp;kHz multibeam echosounder, allowing search swaths 12–15&nbsp;km in width at {{convert|11000|m|ft|0}} depth. The depth accuracy of ''Yokosuka''{{'s}} Seabeam was about 0.1% of water depth (i.e. ± {{convert|110|m|ft|0}} for {{convert|11000|m|ft|0}} depth). The ship's dual GPS systems attained geodetic positioning within double digit meter ({{convert|100|m|ft|0}} or better) accuracy.