The waterways of the Western Archipelago of Indonesia were of high importance for early intra-Asian sea trade. Maritime crossroads in Sumatran waters, particularly the Straits of Bangka, Gaspar and Karimata formed the most frequented sea lanes. Trading ships coming from the Straits of Melaka, the Gulf of Siam and the South China Sea entered the Java Sea through these water passages. By presenting unpublished survey reports on shipwreck sites conducted in this area, I wish to investigate the connective function of these maritime passages in the history of commerce and communication. The archaeological finds portray the various functions of these major sea straits in Asia. Discovered from 2007 to 2010, the wreck sites from the 10th to the 19th century were found partly furnished with large cargos, but most of them had already been disturbed or looted. This large number of archaeological discoveries highlights the fact that the official count of shipwrecks is far too small. There is an urgent need for establishing a find distribution map for historic wreck sites in order to protect these sites.