Staff members of China Marine Surveillance (CMS) head for Zhaoshu Island in Sansha City, south China's Hainan Province, March 10, 2013. A CMS detachment on Sunday started a joint ship-helicopter patrol of the Xisha Islands in the South China Sea. (Xinhua/Wei Hua)

Staff members of China Marine Surveillance (CMS) head for Zhaoshu Island in Sansha City, south China's Hainan Province, March 10, 2013. A CMS detachment on Sunday started a joint ship-helicopter patrol of the Xisha Islands in the South China Sea. (Xinhua/Wei Hua)

Staff members of China Marine Surveillance (CMS) explain laws and regulations of island protection to fishmen on Zhaoshu Island in Sansha City, south China's Hainan Province, March 10, 2013. A CMS detachment on Sunday started a joint ship-helicopter patrol of the Xisha Islands in the South China Sea. (Xinhua/Wei Hua)