U.S. Marines with the Maritime Raid Force, 31st Marine Expeditionary Unit clear a water treatment facility at Koror, Palau, July 21, 2016. The Marines are conducting training in Palau to ensure familiarity with Palau's complex urban environment. The training events were planned out with local authorities to provide an opportunity for realistic training with minimal inconvenience to the community and environment. - U.S. Marines with the Maritime Raid Force, 31st Marine Expeditionary Unit clear a water treatment facility at Koror, Palau, July 21, 2016. The Marines are conducting training in Palau to ensure familiarity with Palau's complex urban environment. The training events were planned out with local authorities to provide an opportunity for realistic training with minimal inconvenience to the community and environment.