The Mexican navy patrol ship ARM Independencia (PO-163) is underway with the Arleigh Burke-class guided-missile destroyer USS Gravely (DDG 107) during a drone exercise for UNITAS Atlantic 2012. UNITAS Atlantic 2012 is an annual naval exercise hosted by the U.S. 4th Fleet and consists of naval forces from 13 different partner nations. (U.S. Navy photo by Mass Communications Specialist 3rd Class Frank J. Pikul/Released)