The NOAA vessel Okeanos Explorer recently tracked the bottom over the Mariana Trench down to 7954 metres with its EM 302 multibeam echosounder, which is theoretically calculated to reach 7000 meters depth.
With a maximum known depth of about 10,916 metres, the Mariana Trench is the deepest part of the oceans anywhere in the world.
The NOAA vessel Okeanos Explorer.
As the only United States ship assigned to systematically exploring our largely unknown oceans, the Okeanos Explorer was fitted with a EM 302 multibeam echo sounder last year in order to provide high-resolution maps of the seafloor.
The National Oceanic Atmospheric Administration (NOAA) operates a wide assortment of hydrographic survey, oceanographic research, and fisheries research vessels and has a full suite of Kongsberg multibeams, including an EM 122 (1x1 Degree) for the ship Ronald H. Brown and an EM 710 (0.5 x 1 Degree) for the ship Rainer.