(kâr´´ĭbē'Әn, kӘrĭb'ēӘn), tropical sea, c.970,000 sq mi (2,512,950 sq km), arm of the Atlantic Ocean, Central America. It is bordered on the N and E by the West Indies archipelago, on the S by South America, and on the W by the Central American isthmus. The Caribbean is linked to the Gulf of Mexico by the Yucatán Channel; to the Atlantic by many straits, of which the Windward Channel and Mona Passage are the most important; and to the Pacific Ocean by the Panama Canal. The Magdalena is the largest river entering the sea; Lake Maracaibo is its largest embayment.
Geologically, the Caribbean Sea consists of two main basins separated by a broad, submarine plateau. Cayman Trench, a trench between Cuba and Jamaica, contains the Caribbean's deepest point (24,721 ft/7,535 m below sea level). The Caribbean's water is clear, warm (75 degrees Fahrenheit/24 degrees Celsius), and less salty than the Atlantic; the basin has a very low tidal range (c.1 ft/.3 m). The Caribbean Sea has a counterclockwise current; water enters through the Lesser Antilles, is warmed, and exits via the Yucatán Channel, where it forms the Gulf Stream. Volcanic activity and earthquakes are common in the Caribbean, as are destructive hurricanes that originate over the sea or in the Atlantic.
Petroleum, iron ore, bauxite, sugar, coffee, and bananas are the main local products traded on the sea. Economically, the region is dependent on U.S. and European patronage and a large tourism industry. The Caribbean Sea has also acted as a barrier, isolating the islands and preventing the mingling of peoples on the scale characteristic of Latin America. In the 1990s, however, the increased need for labor due to the growth of tourism attracted immigrants to some of the islands.
After the Caribbean was visited by Christopher Columbus in 1493, Spain claimed the area, and its ships searched for treasure. With the Spanish discovery of the Pacific Ocean in 1513 the Caribbean became the main route of their expeditions and, later, of convoys. Pirates and warships of rival powers preyed on Spanish ships in the Caribbean. Although Spain controlled most of the sea, Britain, France, the Netherlands, and Denmark established colonies on the islands along the eastern fringe. The 1800s brought U.S. ships into the Caribbean, especially after 1848, when many gold-seekers crossed the sea to reach California via Panama.
After unsuccessful French attempts in the late 1800s to build a canal across Panama, the United States, in 1903, assumed control of the project. The 1914 opening of the Panama Canal paved the way for increased U.S. interest and involvement in this strategic sea, sometimes called the “American Mediterranean.” Several Caribbean islands have U.S. military bases, many of which were established during World War II as support bases to protect the Panama Canal. The naval base at Guantánamo Bay, Cuba (est. 1899) is the oldest U.S. Caribbean base.
U.S. policy since the Monroe Doctrine of 1823 has been to exclude foreign powers from the Caribbean; however, in 1959, Cuba became the first country to come under strong foreign (Soviet) influence. U.S. intervention in the affairs of Caribbean countries, such as the Cuban Missile Crisis of 1962, the landing of U.S. marines at Santo Domingo in 1965 and at Grenada in 1983, and the U.S. invasion of Panama in 1989, reflects the region's importance in U.S. eyes.