Lt. Col. David Nelson swims in the waters of small lake at the Army Training Site Arden Hills, Minnesota Sept. 16, 2012 with a aircrew life preserver helping to keep him afloat. The Airmen of the 133rd Airlift Wing, Minnesota Air National Guard are taking part in their annual survival including survival equipment, lift raft familiarization, parachute disentanglement and rescue techniques. U.S. Air Force Photo by Tech. Sgt. Erik Gudmundson/released