Crewmembers aboard the Coast Guard Cutter Healy retrieve the glider unit of a Wave Glider Unmanned Surface Vehicle from the ocean during an oil in ice exercise in the Arctic Aug. 21, 2014. The Wave Glider's glider unit can propel the device thousands of miles through the ocean using wave motion as its only power source. U.S. Coast Guard photo by Petty Officer 1st Class Shawn Eggert.