Mermaid, built by William Denny and Brothers, Dumbarton, Scotland, was laid down on 8 September 1942, launched on 11 November 1943, and completed 12 May 1944.

[3] Mermaid's first operations were as part of the escort for the Arctic convoy JW 59 to Murmansk in August 1944, with it being credited with a part of sinking the U-boat U-354 on 24 August in conjunction with the destroyer Keppel, the sloop Peacock and the frigate Loch Dunvegan.

[5][6] On the return journey from Murmansk, escorting Convoy RA 59A, Mermaid again took part in sinking a German submarine, this time U-394 on 2 September, in conjunction with a Swordfish aircraft operating from the aircraft carrier Vindex, the destroyers Keppel and Whitehall and the sloop Peacock.

However arriving at Aden en route she learned of the Japanese surrender, and of her recall for service with the Mediterranean Fleet as part of the 33rd Escort Flotilla.

[8] In 1953 she returned to Portsmouth and took part in the Fleet Review to celebrate the Coronation of Queen Elizabeth II.