Milwaukee Deep Milwaukee Deep Milwaukee Deep, also known as The Milwaukee Depth, () is the deepest part of the Atlantic Ocean and is part of the Puerto Rico Trench. It has a maximum depth of at least . It is just north of the coast of Puerto Rico at "Punto Palmas Altas" in Manatí. This ocean floor feature is named for the USS "Milwaukee" (CL-5), a U.S. Navy Omaha class cruiser, which discovered the Milwaukee Deep on February 14, 1939 with a reading of . On August 19, 1952, the U.S. Fish and Wildlife vessel "Theodore N. Gill" obtained a reading of
Sigsbee Deep the ACUF Mexico basin with "Sigsbee deep" as an alternate name is given in the NGA database as 25° N 92° W. There are other features with BGN approved names in the region in recognition of this pioneer in deep ocean sounding and commander of the first true bathymetric survey of the Gulf of Mexico conducted while commanding USC&GS "George S. Blake": Sigsbee Deep The Sigsbee Deep (Mexico basin in the U. S. Board on Geographic Names Advisory Committee on Undersea Features (ACUF) Gazetteer), is a roughly triangular basin that is the deepest part of the Gulf of Mexico named