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Milwaukee Deep is located in Caribbean
Milwaukee Deep
Milwaukee Deep
Location of Milwaukee Deep north of Puerto Rico
Location map Puerto Rico trench - USGS
Perspective view of the sea floor of the Atlantic Ocean and the Caribbean Sea. The Lesser Antilles are on the lower left side of the view and Florida is on the upper right. The purple sea floor at the center of the view is the Puerto Rico trench, the deepest part of the Atlantic Ocean and the Caribbean Sea.

Milwaukee Deep, also known as The Milwaukee Depth, (19°35′N 66°30′W / 19.583°N 66.500°W / 19.583; -66.500) is the deepest part of the Atlantic Ocean and is part of the Puerto Rico Trench.[1] It has a maximum depth of at least 28,365 feet (8,646 m). It is just 76.0 miles (122.3 km) north of the coast of Puerto Rico at Punto Palmas Altas in Manatí.[2][3]

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 28,680 feet (8,740 m).[4][5]

On August 19, 1952, the U.S. Fish and Wildlife vessel Theodore N. Gill obtained a reading of 28,560 feet (8,710 m) at (19°36′N 68°19′W / 19.600°N 68.317°W / 19.600; -68.317), virtually identical with the Milwaukee's reading.

The existence of deep water to the Atlantic Ocean side of the Caribbean has been known for more than a century. One of the area's earliest soundings was obtained June 12, 1852 by Lt. S. P. Lee, U.S. Navy brig Dolphin, with a reading of 22,950 feet (7,000 m) at (26°32′N 60°06′W / 26.533°N 60.100°W / 26.533; -60.100).[6]

See alsoEdit


  1. ^ Vaughn; et al. (1940). "Chart I. - Major Ocean Basins with Depths Exceeding 4000 meters (I-XLV)" (PDF). Retrieved 2014-08-25.
  2. ^ "Milwaukee Depth". Encyclopædia Britannica. 2009. Encyclopædia Britannica Online. 12 October 2009 <>.
  3. ^ Bulent Kastarlak (1958). "Low Cost Housing Development with Aided Self-Help Method in Bayamon, Commonwealth of Puerto Rico" (PDF). Archived from the original (PDF) on 2014-08-26. Retrieved 2014-08-25.
  4. ^ Vaughn; et al. (1940). "Chapter II: The Earth and its Ocean Basins" (PDF). Retrieved 2014-08-25.
  5. ^ Silverstone, Paul (2008). The Navy of World War II: 1922-1947.
  6. ^ The Deepest Sounding in the North Atlantic, J. Lyman, Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences, Vol. 222, No. 1150, A Discussion on the Floor of the Atlantic Ocean (March 18, 1954), pp. 334–336. Published by: The Royal Society. <>