 It is unclear why the ship was so far from its expected route ( shown in red on the map to the right ) , as most ships leaving China for Arabia would have sailed through the South China Sea . They would then turn north @-@ west after passing southern Vietnam , continuing through the Singapore Strait into the Straits of Malacca between Peninsular Malaysia and Sumatra . Belitung is some distance from this route , and it is unclear how the vessel came to be in this area . Belitung is to the south @-@ east of the Singapore Strait by 380 miles ( 610 km ) , and this secondary route is more normal for ships travelling from the Java Sea , which is south of Belitung Island , to the Strait of Malacca 380 miles ( 610 km ) north of the Island . 
