The American Mediterranean Sea is the combined waterbody of the Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

 and the Caribbean Sea

Caribbean Sea

The Caribbean Sea is a sea of the Atlantic Ocean located in the tropics of the Western hemisphere. It is bounded by Mexico and Central America to the west and southwest, to the north by the Greater Antilles, and to the east by the Lesser Antilles....

. The American Mediterranean has a surface area of 4.319 million km² and an average depth of 2216 metres (7,270.3 ft).

The basins of the sea include the Mexican Basin of the Gulf of Mexico, the Yucatan Basin and Cayman Trough

Cayman Trough

The Cayman Trough, is a complex transform fault zone pull apart basin which contains a small spreading ridge on the floor of the western Caribbean Sea between Jamaica and the Cayman Islands...

 of the northwestern Caribbean, and the Columbian and Venezuelan basins of the southern Caribbean.

Watershed

It drains the ~2400000 sq mi (6,215,971.5 km²) area in North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and Caribbean South America

Caribbean South America

Caribbean South America is a region of South America consisting of the nations that border the Caribbean Sea, namely:*Colombia*Venezuela...

 that is the 2nd largest sea watershed.

More than half of the American Mediterranean Sea's watershed is the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 basin of 1236388 sq mi (3,202,230.2 km²) to the east of the Continental Divide of the Americas, while the Rio Grande

Rio Grande

The Rio Grande is a river that flows from southwestern Colorado in the United States to the Gulf of Mexico. Along the way it forms part of the Mexico – United States border. Its length varies as its course changes...

 drains 234759 sq mi (608,023 km²) and the Yucatan Peninsula

Yucatán Peninsula

The Yucatán Peninsula, in southeastern Mexico, separates the Caribbean Sea from the Gulf of Mexico, with the northern coastline on the Yucatán Channel...

 is 76300 sq mi (197,616.1 km²).http://www.britannica.com/EBchecked/topic/654547/Yucatan-Peninsula Central American drainages include those of/to the Belize River

Belize River

Belize River is a 180-mile river in Belize that drains more than one-quarter of the country as it winds along the northern edge of the Maya Mountains across the center of the country to the sea just north of Belize City . However, the Belize River/Mopan River Catchment contains over 45 percent of...

, Gulf of Honduras

Gulf of Honduras

The Gulf or Bay of Honduras is a large inlet of the Caribbean Sea, indenting the coasts of Belize, Guatemala, and Honduras. From north to south, it runs for approximately 200 km from Dangriga, Belize, to La Ceiba, Honduras....

, Caratasca Lagoon

Caratasca Lagoon

The Caratasca Lagoon is a large lagoon in the department of Gracias a Dios in northeastern Honduras. Puerto Lempira, the capital of the department, lies on its shores....

, Nicaraguan Caribbean Lowlands

Geography of Nicaragua

Nicaragua is a country in Central America, bordering both the Caribbean Sea and the North Pacific Ocean, between Costa Rica and Honduras. Approximately the size of Greece or the U.S. state of New York, it is the largest country in Central America...

, Colorado River (Costa Rica)

Colorado River (Costa Rica)

The Colorado River, or the Rio Colorado, in Costa Rica is a tributary of the San Juan River which flows 96 km towards the Caribbean in the northern parts of Heredia and Limón Provinces...

; while in South America

South America

South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 are the Guajira Peninsula

Guajira Peninsula

Guajira Peninsula , is a peninsula in northern Colombia and northwestern Venezuela in the Caribbean Sea...

 and Gulf of Venezuela

Gulf of Venezuela

The Gulf of Venezuela is a gulf of the Caribbean Sea bounded by the Venezuelan states of Zulia and Falcón and by Guajira Department, Colombia...

drainages.