170816-N-IA905-0107 PACIFIC OCEAN (Aug. 16, 2017) Gas Turbine Systems Technician (Electrical) 2nd Class Jordan M. Serck troubleshoots a valve aboard the guided-missile destroyer USS Preble (DDG 88). Preble is underway conducting a composite training unit exercise (COMPTUEX) with the Theodore Roosevelt Carrier Strike Group in preparation for an upcoming deployment. COMPTUEX tests a carrier strike group’s mission-readiness and ability to perform as an integrated unit through simulated real-world scenarios. (U.S. Navy photo by Mass Communication Specialist Seaman Morgan K. Nall/Released)