Tech. Sgt. Andrew Perrin adjusts a block of ice bobbing in the water during the annual Ice Operations Exercise held March 1, 2011, at Joint Base Elmendorf-Richardson’s Six Mile Lake in Alaska. Sergeant Perrin is with JEBR’s 611th Civil Engineer Squadron. Some 60 people from the 611th CES, the U.S. Coast Guard, the Navy's Supervisor of Salvage, the Alaska Department of Environmental Conservation and the Alaska Chadux Corporation participated in the exercise where participants practice various oil spill clean-up drills. (U.S. Air Force photo/Senior Airman Christopher Gross)