The crew aboard Coast Guard Cutter Mackinaw, a 240-foot icebreaker homeported in Cheboygan, Mich., passes the motor vessel AlgoCanada after its down bound transit on the St. Marys River, Dec. 23, 2013. The crew of Mackinaw has been breaking ice alongside ice-breaking partner Canadian Coast Guard Ship Samuel Risley as they maintain tracks through the ice for the numerous vessels still transiting the river. U.S. Coast Guard photo by Ensign Michael Cooper