180906-N-MU198-024 GUAM (Sept. 6, 2018) Sailors assigned to Construction Battalion Maintenance Unit (CBMU) 303 line the perimeter of a tent city with barbed wire in preparation for Valiant Shield, Sept. 6, 2018. Valiant Shield is a U.S. only, biennial field training exercise (FTX) with a focus on integration of joint training in a blue-water environment among U.S. forces. This training enables real-world proficiency in sustaining joint forces through detecting, locating, tracking, and engaging units at sea, in the air, on land, and in cyberspace in response to a range of mission areas. (U.S. Navy photo by Mass Communication Specialist 3rd Class Danny Ray Nuñez Jr./Released)