160328-N-TC720-212 ROTA, Spain (March 28, 2016) - A tugboat helps guide USS Donald Cook (DDG 75) to the pier in Rota, Spain, during a scheduled port visit March 28, 2016. Donald Cook, an Arleigh Burke-class guided-missile destroyer, forward deployed to Rota, Spain is conducting a routine patrol in the U.S. 6th Fleet area of operations in support of U.S. national security interests in Europe. (U.S. Navy photo by Mass Communication Specialist 2nd Class Mat Murch/Released)