Officers wave hands on board and prepare to set sail at a port in Zhoushan, east China's Zhejiang Province, Feb. 21, 2011. The 8th Chinese naval escort flotilla, consisting of frigate Wenzhou and frigate Ma'anshan, departed from Zhoushan on Monday, for the escort mission with comprehensive supply ship Qiandaohu in the Gulf of Aden and Somali waters to protect commercial ships from pirate attacks. [Sina]