USNAVSO and U.S. Fourth Fleet supports USSOUTHCOM joint and combined full spectrum military operations 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 and South American regions.

The extensive operations built up in Brazil were run down swiftly after the end of the war.

In June 1958 Commander, South Atlantic Force, U.S. Atlantic Fleet (COMSOLANT) was established in headquarters at Naval Base Trinidad,[1] and was moved to Roosevelt Roads, Puerto Rico in 1973.

The command consolidates functions previously conducted by the Commander, Western Hemisphere Group, formerly in Mayport, Florida and COMSOLANT, formerly located at Naval Station Roosevelt Roads, Puerto Rico.

In addition to UNITAS, COMUSNAVSO, participates in navy-to-navy exercises, counter-drug operations, port visits, humanitarian missions, disaster relief, and protocol events.