170818-N-FP878-055 ALTLANTIC OCEAN (Aug. 18, 2017) Lt. Daniel Sloan climbs a ladderwell aboard the Arleigh Burke-class guided-missile destroyer USS Donald Cook (DDG 75) during a mobility engineering assessment. Donald Cook is forward-deployed to Rota, Spain, conducting its 6th patrol in the U.S. 6th Fleet area of operations. (U.S. Navy photo by Mass Communication Specialist 1st Class Theron J. Godbold/Released)