A Marine driving a Humvee tackles a four-foot-deep water-fording area at Camp Lejeune, North Carolina Aug. 13, 2014, during exercise Heavy Metal 14. Before the Marines were allowed to cross the water in their vehicles, they had to first navigate the obstacles on foot to check for any unseen dangers. - A Marine driving a Humvee tackles a four-foot-deep water-fording area at Camp Lejeune, North Carolina Aug. 13, 2014, during exercise Heavy Metal 14. Before the Marines were allowed to cross the water in their vehicles, they had to first navigate the obstacles on foot to check for any unseen dangers.