The guided-missile frigate Huangshi (Hull 502) attached to a destroyer flotilla with the navy under the PLA Northern Theater Command deploys smokes during a recent round-the-clock maritime exercise in waters of the Yellow Sea. (eng.chinamil.com.cn/Photo by Wang Guangjie)

The guided-missile frigate Huangshi (Hull 502) attached to a destroyer flotilla with the navy under the PLA Northern Theater Command fires its main gun at mock sea targets during a recent round-the-clock maritime exercise in waters of the Yellow Sea. (eng.chinamil.com.cn/Photo by Wang Guangjie)

The guide missile frigates Xinyang (Hull 501) and Huangshi (Hull 502) attached to a destroyer flotilla with the navy under the PLA Northern Theater Command transit in formation during a recent round-the-clock maritime exercise in waters of the Yellow Sea. (eng.chinamil.com.cn/Photo by Wang Guangjie)

The guide missile frigates Xinyang (Hull 501) and Huangshi (Hull 502) attached to a destroyer flotilla with the navy under the PLA Northern Theater Command transit in formation during a recent round-the-clock maritime exercise in waters of the Yellow Sea. (eng.chinamil.com.cn/Photo by Wang Guangjie)

The guide missile frigates Xinyang (Hull 501) and Huangshi (Hull 502) attached to a destroyer flotilla with the navy under the PLA Northern Theater Command transit in formation during a recent round-the-clock maritime exercise in waters of the Yellow Sea. (eng.chinamil.com.cn/Photo by Wang Guangjie)

The guided-missile frigate Xinyang (Hull 501) attached to a destroyer flotilla with the navy under the PLA Northern Theater Command fires its main gun at mock sea targets during a recent round-the-clock maritime exercise in waters of the Yellow Sea. (eng.chinamil.com.cn/Photo by Wang Guangjie)