A mainland sailor was missing last night after his shipmates were rescued by marine police when their cargo vessel sank off Kau Yi Chau. The 58-metre vessel Yue Hai 108 capsized 500 metres northeast of Kau Yi Chau at 6am when a passing merchant ship reportedly created strong waves, marine harbour divisional commander (operations) Chief Inspector Kong Yiu-man said. The mainland vessel, with nine crew aboard, was carrying 46 containers and had been anchored in the area since arriving from Fujian on August 12. 'One of the crew was found in a life raft and the other seven were on top of a floating container when marine police launches arrived,' Mr Kong said. The eight were taken to Queen Mary Hospital, where they were treated and discharged. An air and sea search was launched after officers learned that a ninth man, 56, was missing. Police were told he may have been asleep in his cabin when disaster struck. A Government Flying Services helicopter, five marine police launches, two fireboats and two Marine Department launches were involved in the search. Divers from the Fire Services Department were also involved but failed to find the man. Forty-five containers had sunk and the remaining one was picked up. A spokeswoman for the Marine Department said marine traffic was not affected.