After a short work-up subsequent to commissioning on 3 February 1943, Athabaskan sailed on 29 March 1943 to patrol the Iceland-Faeroes Passage for blockade runners, but heavy seas damaged her hull, which took five weeks to repair at South Shields.

Athabaskan was heavily damaged by a Henschel Hs 293 glider bomb, dropped by a KG 100 aircraft, during an anti-submarine chase off Cape Ortegal, in the Bay of Biscay, on 27 August 1943.

On 26 April, she assisted in the destruction of the German Elbing-class torpedo boat T29 in the English Channel off Ushant as part of an ‘Operation Tunnel’ mission that included the British cruiser Black Prince, destroyer Ashanti and Canadian Tribals Haida, Huron and Athabaskan.

[5] On 29 April 1944 at about 0300 hours Athabaskan was patrolling with her sister Tribal-class destroyer Haida in support of a British minelaying operation off the coast of France near the mouth of the Morlaix River.

At least one survivor tells of a second torpedo hit fifteen minutes after the first, but the official history of the Royal Canadian Navy attributes the second major explosion to the fires touching off the ammunition magazine.

When Haida quickly departed the area due to the onset of daylight and heightened risk from air and sea attacks, she left behind her motor cutter manned by Leading Seaman W. A. MacLure, Jack Hannam and three volunteers.

After a series of breakdowns and encounters with enemy aircraft, MacLure's motor cutter eventually made landfall in England under Royal Air Force escort just before midnight on 29 April 1944.