SEATTLE - Coast Guard Cold Water Ice Diving Course trainee, Petty Officer 2nd Class Kyle Mellon, drills a hole in the ice of Diamond Lake, Eastern Wash., to test ice thickness, Feb. 16, 2011. The training course aims to familiarize divers with the harsh elements of the Arctic before they depart on polar missions. U.S. Coast Guard photo by Petty Officer 3rd Class Nathan W. Bradshaw.