2001 – RV "Melville" –– The 2.516-ton research vessel "Melville" at the time operated by the Scripps Institution of Oceanography took the Cook Expedition, Leg 6 with chief scientist Patricia Fryer of the University of Hawaii from Guam on 10 February 2001 to the Challenger Deep for a survey titled "Subduction Factory Studies in the Southern Mariana," including HMR-1 sonar mapping, magnetics, gravity measurements, and dredging in the Mariana arc region. They covered all three basins, then tracked -long lines of bathymetry East-West, stepping northward from the Challenger Deep in sidesteps, covering more than north into the backarc with overlapping swaths from their SeaBeam 2000 12-kHz multi-beam echosounder and MR1 towed system. They also gathered magnetic and gravity information, but no seismic data. Their primary survey instrument was the MR1 towed sonar, a shallow-towed 11/12-kHz bathymetric sidescan sonar developed and operated by the Hawaii Mapping Research Group (HMRG), a research and operational group within University of Hawaii’s School of Ocean and Earth Science and Technology (SOEST) and the Hawaii Institute of Geophysics and Planetology (HIGP). The MR1 is full-ocean-depth capable, and provides both bathymetry and sidescan data.