U.S. Marines assigned to Echo Company 4th Reconnaissance Battalion retrieve their gear after swimming 2,000 meters during an amphibious assault operation on the Potomac river at Marine Corps Base (MCB) Quantico, Va., July 21, 2014. The training exercise was part of a week-long jump, dive, breach, and shooting package conducted around various ranges on MCB Quantico. (U.S. Marine Corps photo by Staff Sgt. Ezekiel R. Kitandwe/Released)