Navigation Map (Zhen Lu Tu)

The map was included in Records of Messages from Chong-shan (Zhong Shan Chuan Xin Lu), a book by Xu Baoguang, a deputy title-conferring envoy to Ryukyu in 1721 (the 60th year of the reign of Emperor Kangxi of the Qing Dynasty). Showing the sailing route between China and Ryukyu, the map clearly demonstrates that Diaoyu Dao and its affiliated islands must be passed on the way from China to Ryukyu.