Milwaukee Deep, also known as The Milwaukee Depth, (19°35'N, 66°30'W) is the deepest part of the Atlantic Ocean and is part of the Puerto Rico Trench. It has a maximum depth of at least 27,493 feet (8,380 m). It is just 76.0 miles (122.3 km) north of the coast of Puerto Rico at Punto Palmas Altas in Manatí.[1]
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).
On August 19, 1952, the U.S. Fish and Wildlife vessel Theodore N. Gill on August 19, 1952 obtained a reading of 28,560 feet (8,710 m) in (19°36'N, 68°19'W), 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).[2]