USS Unimak, a 1,766-ton Barnegat class small seaplane tender, was built at Seattle, Washington, and was commissioned in December 1943. She commenced seaplane support duties in the Panama Canal Zone in March 1944, operating first along the Pacific coast of Central and South America and then in the Caribbean. Unimak received repairs at the Boston Navy Yard from December 1944 to March 1945, and then made two voyages to the United Kingdom to transport seaplane personnel and supplies back to the U. S. In July 1945 she departed Norfolk, Virginia, for the Pacific, where she operated first in Hawaii and then in Alaska. She commenced inactivation in December 1945 and was decommissioned in July 1946.

In September 1948 Unimak was loaned to the Coast Guard as the cutter Unimak (WAVP-379, later WHEC-379 and WTR-379). She initially served out of Boston, Massachusetts, on weather station duty, but subsequently performed a wide variety of services, including fishing patrol duty out of New Bedford, Massachusetts, after 1977. She was the last surviving ex-AVP in Coast Guard service when decommissioned in April 1988. She was subsequently scuttled as a fish reef.