U.S. Marine Corps Sgt. Nathaniel McDonald, left,

U.S. Marine Corps Sgt. Nathaniel McDonald, left, demonstrates a combat grip during a martial arts training session aboard the amphibious transport dock ship USS Green Bay (LPD 20) Oct. 4, 2012, in the Pacific Ocean. Green Bay, part of the Peleliu Amphibious Ready Group, was deployed with the amphibious assault ship USS Peleliu (LHA 5), the amphibious dock landing ship USS Rushmore (LSD 47) and embarked Marines with the 15th Marine Expeditionary Unit. (U.S. Navy photo by Mass Communication Specialist 1st Class Elizabeth Merriam/Released)