is a United States Coast Guard Cutter and an icebreaking tug. She is based at Coast Guard Station St. Ignace with a primary area of operation in the Straits of Mackinac including Mackinac Island, Mackinac Bridge, and the northern portions of Lakes Michigan and Huron and occasionally Lakes Superior, Erie and their connecting rivers. Beyond her role as an icebreaker, Biscayne Bay performs search and rescue and law enforcement functions.