The U.S. Fourth Fleet is a United States Navy numbered fleet. It is the Naval Component Command of U.S. Southern Command (USSOUTHCOM). The Fourth Fleet is headquartered at Naval Station Mayport in Jacksonville, Florida. It is responsible for U.S. Navy ships, aircraft and submarines operating in the Caribbean Sea, and the Atlantic and Pacific Oceans around Central and South America. History World War II The 4th Fleet was a major U.S. Navy formation in the South Atlantic Ocean during World War II. It was originally established to protect the U.S. against Axis surface raiders, blockade runners, and submarines. The Fleet was originally a redesignation of the South Atlantic Force. On 12 September 1942, the Brazilian Navy was placed under command of the U.S. Navy's Vice Admiral Jonas Ingram by order of the Brazilian President Vargas. Three days later, on 15 September 1942, Vice Admiral Ingram was appointed as Commander, South Atlantic Force (ComSoLant). Six months later, South Atlantic Force was redesignated the U.S. Fourth Fleet on 15 March 1943. The Fleet worked with Brazil in the South Atlantic using Atlantic Ocean bases at Recife and elsewhere. The fleet was later commanded by Vice Admiral William Munroe. In all, forces deployed to the 4th Fleet sank 18 German U-boats and one Italian submarine, along with sinking or stopping Axis blockade runners. Three years after its establishment, on April 15, 1945, the Fourth Fleet was dissolved and renamed Task Force 27. Admiral Munroe kept the title and command of Commander, South Atlantic Force. In 1946, the U.S. 4th Reserve Fleet was formed to maintain readiness for war; it was disestablished on January 1, 1947. 2008 reactivation On 24 April 2008, Chief of Naval Operations Admiral Gary Roughead announced the reestablishment of the Fourth Fleet. Its formal reestablishment took place on 12 July 2008 at a ceremony at Naval Station Mayport, Florida. The announcement was made before informing foreign governments in the region, several of which expressed concern. The governments of Argentina and Brazil made formal inquiries as to the fleet's mission in the region. In Venezuela, President Hugo Chávez accused the United States of attempting to frighten the people of Latin America and vowed that his country's new Sukhoi Su-30 jets could sink any U.S. ships invading Venezuelan waters. Cuban president Fidel Castro warned that it could lead to more incidents such as the 2008 Andean diplomatic crisis. Mission U.S. Naval Forces