Song Hui Yao (State Regulations of the Song Dynasty) Official Publication (Song Dynasty)

In Song Hui Yao the official publication, "Shitang" (rocky reefs) or "Wanlishitang" (ten thousand-li rocky reefs) was used to refer to Nanhai Zhudao: "To go to China, the maritime route must be taken. A journey of five days takes one to Bosilan, Kunlun Ocean and Chân Lạp successively. After a few more days, one reaches the State of Binda Ye (lang), and then Chiêm ThànhChampa. Within ten days, he shall reach the ocean, to the southeast of which there is a Shitang known by the name Wanli (ten thousand li). With its tricky rapid waters and multiple submerged reefs, it has sunken seven to eight of every ten ships sailing across. After passing the shore at Wushan, one reaches Jiaozhi; and after five more days, he reaches the Prefecture of Qinlian State. All calculations are based on the premise of downwind."