United States Navy (1943–1967)

Hayter was launched by Charleston Navy Yard, con 11 November 1943; sponsored by Mrs. Maurine K. Hayter, widow of the namesake; and commissioned at Charleston on 16 March 1944.

Hayter departed Charleston on 1 April 1944 for shakedown training off Bermuda, and subsequently was assigned to an escort division for Atlantic duty. Between 1 June and 30 November 1944, she made three voyages to Europe, two from Norfolk, Virginia to Bizerte and one from Casco, Maine, to Bizerte. During the voyages Hayter provided anti-submarine protection and transferred the division doctor to many merchant ships in the convoy needing medical assistance.

Hayter sailed on 2 January 1945 on a special duty in the Atlantic, with other units of Escort Division 62. Their assignment to find and sink U-248, which had been sending vital weather reports to Axis units from the Azores area. The ships conducted several search sweeps before Hayter made contact with the submarine on 16 January, and after a series of lethal depth charge attacks lasting two hours the submarine was sunk. Hayter patrolled the Azores for a time, then joined a convoy screen for the voyage back to Norfolk, arriving on 5 February 1945.

Departing Casco Bay on 17 March, Hayter and her escorts proceeded into the north Atlantic for anti-submarine sweeps in the Iceland area. The ships made a depth charge attack on 10 April, but did not score a definite kill. The group returned to NS Argentia, Newfoundland, on 14 April, and departed four days later for anti-submarine barrier patrol, cruising between escort carriers Bogue (CVE-9) to the south, and Core (CVE-13), to the north. Contact was made on 23 April and all ships searched without avail until the next day, when escort Frederick C. Davis (DE-136) reported contact on her starboard bow.

As Hayter maneuvered to attack, Frederick C. Davis was struck by a torpedo on her port side amidships, breaking her in two. As the stricken ship settled and sank, Hayter began rescue operations, and despite rough seas, sharks, and the threat of further attacks, managed to save 65 survivors and recover 12 of the dead from the sea. Three of the survivors were revived by artificial respiration given by members of Hayter's crew. In the meantime, the other escorts had closed in on the submarine, U-546, and forced it to the surface. Guns quickly sank the U-boat and her captain was later made prisoner.

Hayter arrived Argentia on 6 May and sailed two days later for Philadelphia Navy Yard via Boston. She arrived on 22 May and began her conversion to a Charles Lawrence-class high speed transport, her designation becoming APD-80 on 1 June 1945.

Emerging as a high speed transport, Hayter departed Philadelphia on 13 August 1945 for her refresher training off Guantanamo Bay. She subsequently operated out of Norfolk and Newport in training operations until 30 October, when she departed Norfolk for Jacksonville, Florida.

At Jacksonville, Hayter was placed in the Reserve Fleet at Green Cove Springs, Florida, decommissioned on 19 March 1946 and was later moved to the Texas group, where she remained until struck on 1 December 1966.

Republic of Korea Navy (1967–1986)

Transferred to South Korea on 23 July 1967, the ex-Hayter was commissioned into the South Korean Navy in August of that year as gunboat ROKS Jonnam (PG-86) (also spelled Jon Nam). Reclassified as escort transport APD-86 in 1972, Jonnam was purchased outright by South Korea on 15 November 1974, redesignated APD-827 in 1980, and again to DE-827 in 1982. She was stricken in 1986.