GULF OF MEXICO - Chief Petty Officer James Parrish, a gunner's mate, fires a .50 caliber machine gun during a gunnery exercise onboard Coast Guard Cutter Bertholf, July 2, 2008. During the exercise, crewmembers performed a structural test fire designed to test the structural integrity of the mount. U.S. Coast Guard photo by Petty Officer 3rd Class Michael Anderson