Capel was attached to 1st Escort Group based at Belfast from 9 April 1944.

After patrols in the area between the Scottish Isles and the Irish Sea, Capel was anchored in Moelfre Bay, Anglesey to await "D-Day". She sailed on 5 May 1944 to join the massive anti-submarine screen patrolling the western end of the English Channel, in order to protect the Normandy landings of 6 June 1944. Capel returned to Belfast on 18 June to rest.

After the port of Cherbourg was captured and cleared the Capel and her Escort Group escorted convoys across the Channel, to and from Cherbourg with rest periods spent at Plymouth. In late 1944 the group shifted operations to the eastern end of the Channel, patrolling the convoy route to the newly liberated port of Antwerp.

At 14.14 hours on 26 December 1944 Capel and the rest the Escort Group were patrolling 10 nmi (19 km; 12 mi) east-northeast of Cherbourg when the German submarine U-486 sighted the group and fired three T5 torpedoes; one of which hit Capel and another Affleck.

Affleck was towed to port, but declared a total loss, while Capel sank. The survivors were picked up by American MTBs and taken to Cherbourg. Her commander, Lieutenant B.G. Heslop, DSC, eight officers, and 67 men were lost. [Wikipedia]