180927-N-RI884-0571 SOUTH CHINA SEA (Sept. 27, 2018) Marines assigned to the 31st Marine Expeditionary Unit fire weapons including a light armored vehicle's M242 Bushmaster 25mm chain gun at a target during a Defense of the Amphibious Task Force (DATF) drill on the flight deck of the amphibious assault ship USS Wasp (LHD 1). As part of the DATF, the Wasp Amphibious Ready Group (ARG) and 31st MEU, assumed a security posture, to simulate traveling through potentially dangerous waters. Wasp, flagship of the Wasp ARG, with embarked 31st MEU, is operating in the Indo-Pacific region to enhance interoperability with partners and serve as a ready-response force for any type of contingency. (U.S. Navy photo by Mass Communication Specialist 1st Class Daniel Barker/Released)