When launched, she was the largest icebreaker in use by Canada post-World War II until CCGS John A. Macdonald was put in service.

[5] Following completion of her sea trials, D'Iberville sailed to England as part of Canada's representation at Queen Elizabeth II's coronation review along with warships from the Royal Canadian Navy.

[3] In 1953, on the icebreaker's first Arctic voyage, D'Iberville helped establish the Royal Canadian Mounted Police post at Alexandria Fjord on Ellesmere Island.

Howe participated in the controversial forced resettlement of Inuit families from Port Harrison in Northern Quebec to Ellesmere Island.

[6] On 29 April 1959, the Saint Lawrence Seaway was opened for the first time and D'Iberville and CGS Montcalm were the first ships to transit the lock at Saint-Lambert, Quebec.

[7] In 1962, like all icebreaking vessels of the Department of Transport's Marine Service, she was transferred to the newly created Canadian Coast Guard.