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.

[1] Three days later, on 15 September 1942, Vice Admiral Ingram was appointed as Commander, South Atlantic Force (ComSoLant).

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.

[2] On 24 April 2008, Chief of Naval Operations Admiral Gary Roughead announced the reestablishment of the Fourth Fleet.

In Venezuela, President Hugo Chávez accused the United States of attempting to frighten the people of Latin America[4] and vowed that his country's new Sukhoi Su-30 jets could sink any U.S. ships invading Venezuelan waters.

Naval Forces 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.