Petty Officers 3rd Class Ryan Brookes and Agustin Foguet, both damage controlmen in the Coast Guard Cutter Polar Star’s engineering department, search for a hairline fracture on a piece of the cutter’s reduction gear while underway in McMurdo Sound, Antarctica, Jan. 13, 2016. The reduction gear is used to turn the high speed of the icebreaker’s turbines into low speed, high torque motion for propulsion. (U.S. Coast Guard photo by Petty Officer 2nd Class Grant DeVuyst)