 On 1 June 2009, sonar mapping of the Challenger Deep by the Simrad EM120 multibeam sonar bathymetry system aboard the R/V "Kilo Moana" indicated a maximum depth of .The sonar system uses phase and amplitude bottom detection, with an accuracy of better than 0.2% of water depth (this is an error of about 22 meters at this depth).The ocean can be conceptualized as being divided into various zones, depending on depth, and presence or absence of sunlight.