Royal Navy

After working up, Candytuft was assigned to the Western Approaches Escort Force for service as a convoy escort. In this role she was engaged in all the duties performed by escort ships; protecting convoys, searching for and attacking U-boats which attacked ships in convoy, and rescuing survivors.

Candytuft was involved in one convoy battle. In December 1940, she was part of the escort to convoy OG 46, during which two ships were sunk. In 18 months service, she escorted 13 North Atlantic and two Gibraltar convoys, assisting in the safe passage of over 500 ships, though some were lost subsequently.^[3] In September 1941, while with HX 148 Candytuft suffered a boiler explosion. she was taken under tow to New York, where she underwent repairs, but was out of action for the next four months. In March 1942, while still at New York, Candytuft was transferred to the United States Navy.

United States Navy

Following the entry of the United States into the war the US Navy was in need of anti-submarine warfare vessels, and to meet this need a number of ships were transferred from the Royal Navy as part of a reverse Lend-Lease arrangement. Candytuft was transferred on 4 March 1942, but required an extensive refit; she was finally commissioned into the USN on 11 June 1942 as USS Tenacity, one of the Temptress-class gunboats. Initially employed as a convoy escort in the Caribbean, Tenacity was moved south in September 1942 to join the US 4th Fleet, the South Atlantic escort force, based in Trinidad. After 17 months service there Tenacity was moved, in January 1944, to the Eastern Sea Frontier, based at Boston. There she was employed until the end of hostilities in August 1945, when she was returned to the Royal Navy. As Candytuft once more she was stricken in September 1945.^[4]