170719-M-UH172-072 PACIFIC OCEAN (July 19, 2017) U.S. Marines assigned to 1st Marine Logistics Group watch landing craft air cushion vehicles land aboard the USNS John Glenn during exercise Pacific Horizon 2017, July 19, 2017. The role of these Marines include ground guiding the vehicle and cleaning them before storage. Pacific Horizon 2017 is a Maritime Prepositioning Force (MPF) exercise designed to train I Marine Expeditionary Force (MEF) and components of Naval Beach Group 1 (NBG-1) Marines and Sailors on arrival and assembly operations. (U.S. Marine Corps photo by Lance Cpl. Roxanna Gonzalez)