Southern Command (USNAVSO) and the Fourth Fleet support USSOUTHCOM joint and combined full-spectrum military operations. They do this by providing principally sea-based forward presence to ensure freedom of maneuver in the maritime domain, to foster and sustain cooperative relationships with international partners, and to fully exploit the sea as maneuver space in order to enhance regional security and promote peace, stability, and prosperity in the Caribbean, Central American, and South American regions. The Fleet has five missions: support for peacekeeping, humanitarian assistance, disaster relief, traditional maritime exercises, and counterdrug support operations. Organization Commander, USNAVSO (COMUSNAVSO) also serves as the Navy component commander for USSOUTHCOM. U.S. Fourth Fleet is responsible for U.S. Navy ships, aircraft and submarines operating in the USSOUTHCOM area of responsibility, which encompasses the Caribbean, Central America, South America, and surrounding waters. It is an organizational fleet staffed to fulfill a planning and coordination mission; as part of its 2008 reestablishment, no vessels are permanently assigned to the Fourth Fleet. Ships home-ported in the United States Fleet Forces Command and United States Third Fleet routinely deploy to the Fourth Fleet area of responsibility (AOR), during which time they are under the operational control of the Fourth Fleet commander. Fourth Fleet headquarters is co-located with USNAVSO headquarters in Naval Station Mayport, Florida, and is commanded by a two-star rear admiral. Fourth Fleet Commanders Vice Admiral Jonas H. Ingram (September 1942 11 November 1944) Vice Admiral William R. Munroe (11 November 1944 15 April 1945) Vice Admiral Thomas R. Cooley (1945 mid 1946) Vice Admiral Daniel E. Barbey (September 1946 March 1947) Vice Admiral Charles McMorris (mid-1947 July 1948) Rear Admiral Joseph D. Kernan (1 July 2008 12 June 2009) Rear Admiral Victor G. Guillory (12 June 2009 5 August 2011) Rear Admiral Kurt W. Tidd (5 August 2011 22 June 2012) Rear Admiral Sinclair M. Harris (22 June 2012 17 April 2014) Rear Admiral George W. Ballance (17 April 2014 12 August 2016) Rear Admiral Sean Buck (12 August 2016 21 May 2019) Rear Admiral Donald D. Gabrielson (21 May 2019 present) See also United States Fleet Forces Command United States Second Fleet United States Third Fleet United States Fifth Fleet United States Sixth Fleet United States Seventh Fleet United States Tenth Fleet United States Naval Support Detachment, São Paulo References Suggested reading External links COMUSNAVSO/C4F Official Website Numbered Fleets by the Federation of American Scientists Navy Times: 4th