USNS Coastal Sentry (T-AGM-15)

USS Somerset (AK-212) was originally a U.S. Navy Alamosa-class cargo ship built for service in World War II, and was later re-acquired from the U.S. Air Force in 1964 as the USNS Coastal Sentry (T-AGM-15), a missile range instrumentation ship.

Built in Sturgeon Bay, Wisconsin
The third ship to be so named by the Navy, Somerset (AK-212) (ex-MC hull 2166) was laid down on 9 October 1944 by the Leathern D. Smith Shipbuilding Co., Sturgeon Bay, Wisconsin; launched on 21 January 1945; sponsored by Mrs. Fred Bradley; acquired by the Navy from the U.S. Maritime Commission on 20 September 1945; and commissioned the same day.

Inactivity due to war's end
Somerset was acquired for Navy use as a cargo ship; but, due to the cessation of hostilities with Japan, she saw no naval service. She was returned to the U.S. Maritime Commission on 2 November 1945, renamed Coastal Sentry, and struck from the Navy List for the first time on 5 December 1945.

Service as an Air Force ship
Coastal Sentry was acquired by the U.S. Air Force and was used as a missile range instrumentation ship which operated as USAFS Coastal Sentry on the U.S. Air Force's Eastern Test Range during the late 1950s and early 1960s. Coastal Sentry operated under an Air Force contract with Pan American Airways Guided Missile Range Division headquartered in Cocoa Beach, Florida.

Coastal Sentry was assigned to the South Atlantic Ocean and the Caribbean area, and provided the Air Force with metric data on intercontinental ballistic missiles launched from the Cape Canaveral Air Force Station (CCAFS) in Florida.

Coastal Sentry operated in the intercontinental ballistic missile re-entry area near Ascension Island, and was home-ported out of Recife, Brazil.

Acquisition by the Navy
Coastal Sentry was acquired from the U.S. Air Force by the U.S. Navy in 1964 which placed her out of service in 1972. Operational data while on U.S. Navy service on this vessel is lacking.

Inactivation
Coastal Sentry was struck from the Navy List (date unknown), and was subsequently returned to MARAD for lay up in the National Defense Reserve Fleet. Her ultimate fate is not known.