The vessel, based in Prescott, Ontario, will conduct icebreaking and buoy tending operations on the Great Lakes and St. Lawrence River in Ontario and Quebec. 

The Coast Guard’s Great Lakes operating area extends about 2,400 kilometers along the Canada-U.S. border, from the St. Lawrence River to the western end of Lake Superior. The agency said the region is a priority because much of Canada’s population lives within the Great Lakes basin. 

The Judy LaMarsh was purchased by the Canadian Coast Guard in 2021. From 2023 to 2025, it underwent conversion and refit work at Newdock St. John’s Dockyard Limited in St. John’s, Newfoundland and Labrador. 

The work included refurbishment of the vessel’s propulsion, communications and navigation systems, upgrades to crew workspaces and accommodations, and installation of a new buoy crane. 

The vessel entered service in December 2025 and is the fourth interim icebreaker purchased by the Coast Guard. The other three are the CCGS Jean Goodwill, CCGS Vincent Massey and CCGS Captain Molly Kool. The vessels were acquired to supplement the existing fleet during vessel life-extension and repair periods. 

The Judy LaMarsh is one of three large Coast Guard vessels operating on the Great Lakes. The CCGS Samuel Risley and CCGS Griffon also provide icebreaking services during the winter. 

The ship is named for the late Judy LaMarsh, one of the first women to serve as a federal Cabinet minister. She was instrumental in the development of innovative federal programs, including Medicare and the Canada Pension Plan.