USCGC Half Moon (WAVP-378)

USCGC Half Moon (WAVP-378), later WHEC-378, was a Casco-class United States Coast Guard cutter in service from 1948 to 1969.

Construction and U.S. Navy service
Half Moon began life as the United States Navy Barnegat-class seaplane tender USS Half Moon (AVP-26). She was laid down on 10 March 1942 by Lake Washington Shipyard at Houghton, Washington, launched on 12 July 1942, and commissioned into the U.S. Navy on 15 June 1943. She served in the New Guinea campaign and Philippines campaign during World War II, and at Okinawa and in the Philippines postwar. She was decommissioned on 4 September 1946 and placed in reserve.

Transferred to the United States Coast Guard
Barnegat-class ships were very reliable and seaworthy and had good habitability, and the Coast Guard viewed them as ideal for ocean station duty, in which they would perform weather reporting and search and rescue tasks, once they were modified by having a balloon shelter added aft and having oceanographic equipment, an oceanographic winch, and a hydrographic winch installed.

The U.S. Navy loaned Half Moon to the United States Coast Guard on 30 July 1948. After undergoing conversion for Coast Guard use, she was commissioned into the Coast Guard on 14 September 1948 as USCGC Half Moon (WAVP-378).

Atlantic operations 1948-1967
Half Moon was stationed at Staten Island and Governors Island in New York City throughout her Coast Guard career. Her primary duty was to serve on ocean stations in the Atlantic Ocean to gather meteorological data. While on duty in one of these stations, she was required to patrol a 210-square-mile (544-square-kilometer) area for three weeks at a time, leaving the area only when physically relieved by another Coast Guard cutter or in the case of a dire emergency. While on station, she acted as an aircraft check point at the point of no return, a relay point for messages from ships and aircraft, as a source of the latest weather information for passing aircraft, as a floating oceanographic laboratory, and as a search-and-rescue ship for downed aircraft and vessels in distress, and engaged in law enforcement operations.

On 24 August 1951 and 25 August 1951, Half Moon assisted the merchant ship Castello Guadalest in the Atlantic at Latitude 39°30’ North, Longitude 58°32’ West.

While in Bermuda on a United States Coast Guard Reserve training cruise, Half Moon helped civil authorities in Bermuda fight a fire aboard the merchant ship Coastal Service at Ordnance Wharf, St. Georges, Bermuda, on 14 August 1963.

Half Moon was reclassified as a high endurance cutter and redesignated WHEC-378 on 1 May 1966. Her loan period from the U.S. Navy came to an end on 26 September 1966, when she was transferred permanently from the Navy to the Coast Guard.

On 11 January 1967, Half Moon seized four American fishing vessels seven nautical miles (13 kilometers) northwest of Dog Rocks following a shooting incident in which one person was killed and another wounded.

Vietnam War service 1967
Half Moon sailed from New York Harbor on 1 April 1967 under the command of Commander Emmett G. McCarthy, bound for Pearl Harbor, Hawaii, and an assignment to Coast Guard Squadron Three. The squadron, which was designated Task Unit 70.8.6, was activated at Pearl Harbor, Hawaii, on 24 April 1967 when its commander, Captain John E. Day, hoisted his pennant aboard his flagship, Coast Guard cutter USCGC Gresham (WHEC-387).

Coast Guard Squadron Three was tasked to operate in the South China Sea in conjunction with U.S. Navy forces in Operation Market Time, the interdiction of communist coastal arms and munitions traffic along the coastline of Vietnam during the Vietnam War. The squadron's other Vietnam War duties included fire support for ground forces, resupplying Coast Guard and Navy patrol boats, and search-and-rescue operations. Serving in the squadron with Gresham and Half Moon were cutters USCGC Yakutat (WHEC-380), USCGC Barataria (WHEC-381), and USCGC Bering Strait (WHEC-372); like Half Moon and Gresham, they all were former Navy Barnegat-class ships. They departed Pearl Harbor on 26 April 1967 and reported to Commander, United States Seventh Fleet, for Market Time duty on 4 May 1967. They were joined by Navy radar picket destroyer escorts (DERs) of Escort Squadrons 5 and 7.

The ten Market Time ships arrived at Subic Bay in the Philippines on 10 May 1967. The five Coast Guard cutters and five Navy destroyer escorts continuously manned four Market Time stations off Vietnam, while only Navy warships served on two Taiwan patrol stations. One ship rotated duty as the station ship in Hong Kong.

During her tour, Half Moon conducted nine naval gunfire missions in support of forces ashore. On 12 September 1967 she was ordered to fire on an enemy build-up in An Xugen Province; her gunfire killed at least one enemy soldier and destroyed three Viet Cong fortifications on that occasion. During her tour, she was credited with killing at least 13 Viet Cong soldiers, destroyed 64 military emplacements and structures, and sinking four sampans.

Half Moon also served as a home base for 50-foot (15.25 m) U.S. Navy fast patrol craft (or "Swift boats") and participated in search and rescue operations.

Half Moon concluded her Vietnam War tour on 29 December 1967.

Atlantic operations 1968-1969
Half Moon returned from Vietnam to her home port at New York City on 22 January 1968 and resumed her rotuine Coast Guard operations in the Atlantic. On 11 July 1968 she helped to evacuate an injured crewman from the West German merchant ship Brunsdeich.

Decommissioning and disposal
The Coast Guard decommissioned Half Moon on 15 July 1969. She was sold for scrapping on 29 April 1970 to Cantieri Navali, Genoa, Italy, for a bid price of $66,000 (USD).