Grandmere was commissioned at Montreal on December 11, 1941. En-route to Halifax she broke down in the Gulf of St. Lawrence on December 21, and was towed to Sydney by HMCS Kamsack. Later that month, while alongside at Sydney undergoing repairs, she suffered serious damage to her No. 2 boilers and was taken to Pictou for repairs, which were not completed until May, 1942. She finally arrived at Halifax, her original destination, on May 5. She served for varying periods with WLEF, Sydney Force, Halifax Force, and Halifax Local Defence Force. On October 11, 1942, while with Sydney Force, she rescued 101 survivors of the passenger ferry Caribou, torpedoed in the Cabot Strait. In July 1943, she had a seven-week refit at Louisbourg and underwent a second major refit at Sydney and Halifax in September, 1944, following which she worked up in Bermuda in February, 1945. The ship was paid off at Sydney on October 23, 1945, and placed in reserve at Shelburne. Sold in 1947, she was modified for use as a yacht, first renamed Elda and later, Jack's Bay.