A sailor assigned to a naval vessel training center under the PLA Northern Theater Command practice sending light signals aboard the guided-missile destroyer Nanchang (Hull 101) during a recent 10-day maritime continuous training exercise. (eng.chinamil.com.cn/Photo by Zou Xiangmin)

The guided-missile destroyer Nanchang (Hull 101) attached to a naval vessel training center under the PLA Northern Theater Command steams to occupy an attack position in an undisclosed sea area during a recent 10-day maritime training exercise. (eng.chinamil.com.cn/Photo by Zou Xiangmin)

The guided-missile frigate Datong (Hulll 580, Rear) and the guided-missile destroyer Nanchang (Hull 101, Front) attached to a naval vessel training center under the PLA Northern Theater Command steam in tactical formation to occupy attack positions in an undisclosed sea area during a recent 10-day maritime training exercise. (eng.chinamil.com.cn/Photo by Zou Xiangmin)

The guided-missile frigate Datong (Hulll 580, Rear) and the guided-missile destroyer Nanchang (Hull 101, Front) attached to a naval vessel training center under the PLA Northern Theater Command steam in tactical formation to occupy attack positions in an undisclosed sea area during a recent 10-day maritime training exercise. (eng.chinamil.com.cn/Photo by Zou Xiangmin)

The guided-missile frigate Datong (Hulll 580, Rear) and the guided-missile destroyer Nanchang (Hull 101, Front) attached to a naval vessel training center under the PLA Northern Theater Command steam in tactical formation to occupy attack positions in an undisclosed sea area during a recent 10-day maritime training exercise. (eng.chinamil.com.cn/Photo by Zou Xiangmin)

The guided-missile destroyer Nanchang (Hull 101) attached to a naval vessel training center under the PLA Northern Theater Command fires its main gun against mock targets on the shore during a recent 10-day maritime continuous training exercise. (eng.chinamil.com.cn/Photo by Zou Xiangmin)