Delegates' caps are seen at the rest hall during the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming)

Delegates greet each other during the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming) 
 

Reporters work during the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming)

Participants attend the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming)

Delegates enter the hall during the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming)

Participants attend the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming)

Participants attend the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming)

Delegates take photos during the 14th Western Pacific Naval Symposium in Qingdao, east China's Shandong Province, April 22, 2014. A biennial conference of the Western Pacific Naval Symposium opened in Qingdao Tuesday. (Xinhua/Zha Chunming)