USS Milwaukee (CL-5) While steaming north of Hispaniola and Puerto Rico on 14 February 1939, "Milwaukee" discovered the deepest place in the Atlantic Ocean. The spot—which has a depth of —is now known as the "Milwaukee Deep". By January 1941, the ship had returned to Cruiser Division 2 which was now assigned to the Caribbean Patrol, commanded by Rear Admiral Jonas H. Ingram, part of the Neutrality Patrol established after the war began. Cruiser Division 2 was ordered to patrol the Atlantic between Trinidad, the Cape Verde Islands and the eastern bulge of Brazil in April, although "Milwaukee" was not immediately available. The
Challenger Deep multibeam echosounder technologies a depth uncertainty of ± (95% confidence level) on 9 degrees of freedom and a positional uncertainty of ± (2drms) remain and the location of the deepest depth recorded in the 2010 mapping conducted by the US Center for Coastal & Ocean Mapping/Joint Hydrographic Center (CCOM/JHC) aboard is at (). In November 2016 sonar mapping of the Challenger Deep area was conducted by the Royal Netherlands Institute for Sea Research (NIOZ)/GEOMAR Helmholtz Centre for Ocean Research Kiel aboard RV "Sonne". Using a Kongsberg Maritime EM 122 multibeam echosounder system coupled to positioning equipment that can determine latitude