in rescuing during her transit of the Northwest Passage. John A. Macdonald made a double transit from the east to west and returned west to east. During the rescue, John A. Macdonald broke her starboard propeller in heavy ice; the propeller is on display by the Dartmouth Ferry Terminal, Dartmouth, Nova Scotia. John A. Macdonald was assisted by the United States Coast Guard icebreakers Northwind and In 1974 the merchant vessel Atlantean I was damaged on Lake Ontario, received repairs at Montreal and Quebec City and failed to pay for them. An order of arrest was produced but the vessel sailed without authorization. In February 1975, the Gulf of St. Lawrence was filled with ice and John A. MacDonald was sent to intercept the ship, now renamed Answer. Stuck in ice and boarded by lawyers bearing the warrants, the captain of the merchant vessel refused to sail for Gaspé, Quebec. On 28 February, Royal Canadian Mounted Police and Canadian Coast Guard personnel were placed on board the merchant and the two ships sailed for Sept-Îles, Quebec. However, as soon as Answer was free of the heavy ice, the ship broke escort and fled for the Atlantic. After legal arguments were heard over the right of Canada to seize the vessel, the ship was boarded a third time, the crew taken off and Answer and John A. Macdonald arrived at Sept-Îles on 7 March. Also in 1975, John A. Macdonald made a partial transit of the Northwest Passage, westward, through Lancaster Sound, Peel Sound and Victoria Strait, and sailed to aid CCGS Camsell again after the smaller Coast Guard ship was damaged in the Western Arctic. In 1977, the ship was chartered to Dome Petroleum. During 1978 John A. Macdonald made an east to west partial transit of the Northwest Passage, traveling on charter to Dome Petroleum, through Lancaster Sound, Prince of Wales Strait and the Beaufort Sea. During the winter of 1978–79, the vessel was laid up. In 1979, the vessel made another partial transit of the Northwest Passage, west to east, returning eastward from a charter operation. John A. Macdonald returned to Coast Guard service in 1980 and supported the search that confirmed the wreck of , which had been crushed by ice and sank in the Arctic Ocean in 1853. The following year, John A. Macdonald escorted a factory barge to Little Cornwallis Island where the barge was