A 2009 sonar mapping of the Challenger Deep from the "Kilo Moana" found a spot with a depth of (6.82 miles). The sonar system has an accuracy of better than 0.2% of water depth. <ref name="Daily reports for R/V KILO MOANA"></ref><ref name="Scientic Equipment aboard the R/V KILO MOANA"></ref> Water pressure is more than a thousand times as great as at the surface.