Sailors aboard a rigid-hull inflatable boat (RHIB) deployed by the guided-missile destroyer Qiqihar (Hull 121) practice attaching the boat to a mooring buoy and then releasing it during a 7-day round-the-clock exercise centered on maritime offensive and defensive training. (Photo: eng.chinamil.com.cn)

Sailors man the rails on the forecastle of the guided-missile destroyer Qiqihar (Hull 121) as the vessel steams in astern formation with a comprehensive supply ship prior to a replenishment-at-sea operation during a 7-day round-the-clock exercise centered on maritime offensive and defensive training.(Photo: eng.chinamil.com.cn)

A ship-borne helicopter attached to the navy under the PLA Northern Theater Command lifts off from the flight deck of the guided-missile destroyer Qiqihar (Hull 121) during a 7-day round-the-clock exercise centered on maritime offensive and defensive training.(Photo: eng.chinamil.com.cn)