Petty Officer 1st Class Lisa Sanders, an independent-duty health services technician, instructs crew members aboard the Coast Guard Cutter Polar Star, a heavy icebreaker homeported in Seattle, on proper stretcher bearer procedures while underway in McMurdo Sound near Antarctica, Jan. 21, 2015. Polar Star's crew is underway in support of Operation Deep Freeze, part of the U.S. Antarctic Program, managed by the National Science Foundation. (U.S. Coast Guard photo by Petty Officer 1st Class George Degener)