United States Naval Forces Southern Command:

​United States Naval Forces Southern Command (USNAVSO) was established on February 17, 2000 and headquartered at Naval Station Roosevelt Roads, Puerto Rico, later relocated to Naval Station Mayport, Florida in early 2004. USNAVSO serves as a main link between the U.S. Navy and the navies of South America, Central America, and the Caribbean, and is at the forefront of U.S. engagement in the Western Hemisphere. The command consolidates functions previously conducted by the former Western Hemisphere Group, Mayport, Florida and former South Atlantic Force, U.S. Atlantic Fleet (SOLANT), Naval Station Roosevelt Roads, Puerto Rico.  USNAVSO was built around the core of SOLANT, which was originally established on September 15, 1942 eventually headquartered at Roosevelt Roads, Puerto Rico in 1973.  SOLANT had participated in annual "UNITAS" deployments around South America since 1960 and routinely deployed to Africa for the West African Training Cruise since 1980. 

 In addition to UNITAS, USNAVSO participates in Navy and joint exercises, counter-illicit trafficking operations, port visits, humanitarian missions, disaster relief and protocol events. USNAVSO exercises military command and control of all assigned/allocated ships and units, and serves as the Navy component command to U.S. Southern Command (USSOUTHCOM) with respect to naval matters in the region.


U.S. Fourth Fleet:

U.S. Fourth Fleet employs maritime forces in cooperative maritime security operations in order to maintain access, enhance interoperability, and build enduring partnerships that foster regional security in the USSOUTHCOM AOR.
Chief of Naval Operations (CNO) Admiral Gary Roughead announced the reestablishment of U.S. Fourth Fleet on April 24, 2008. He officially reestablished U.S. Fourth Fleet effective May 5, 2008 with a formal ceremony held at Naval Station Mayport on July 12, 2008. U.S. Fourth Fleet was a major U.S. Navy command in the South Atlantic Ocean during World War II. Established on March 15, 1943 to protect the U.S. against raiders, blockade runners and enemy submarines, it was fully dissolved in February 1950 when responsibilities were taken over by U.S. Second Fleet.

U.S. Fourth Fleet headquarters is co-located with U.S. Naval Forces Southern Command (USNAVSO) at Mayport, Florida.  U.S. Fourth Fleet Commander is also Commander, U.S. Naval Forces Southern Command (COMUSNAVSO). U.S. Fourth Fleet is responsible for U.S. Navy ships, aircraft and submarines operating in the USSOUTHCOM area of operations (AOR), which encompasses the Caribbean, Central and South America and surrounding waters..