uscgc "mackinaw" (wagb-83) is a vessel specifically designed for ice breaking duties on the great lakes. lr number: 6119534 according to the ice breaker mackinaw maritime museum, the vessel has been known as the "queen of the great lakes" and "the largest icebreaker on the great lakes"; the site states that "she was built ... during world war ii to meet the heavy demands of war materials and transportation during the winter months".