170720-M-HF454-036 PACIFC OCEAN (July, 18, 2017) Marines assigned to the 15th Marine Expeditionary Unit (15th MEU) conduct a rifle combat optic zero recalibration aboard the amphibious transport dock ship USS San Diego (LPD 22). The 15th MEU and America Amphibious Ready Group are deployed to the U.S. 3rd, 5th, and 7th Fleet areas of operation as a crisis response and contingency force. (U.S. Marine Corps photo by Cpl. Timothy Valero/Released)