The USCGC Mackinaw is an icebreaker that was specifically built for the Great Lakes. Commissioned in 1944, it is the oldest icebreaker in commission and is scheduled to be replaced in the near future. The design was modified from the Wind Class icebreaker to include a reduced draft and greater beam. Top speed is 18.7 knots and has a crew of 75. The patch depicts the ship with a red hull, which had been changed from white in recent years.