The Indian Ocean and its adjoining seas, from the Middle East and East Africa to Southeast Asia, have been witness to the nautical ventures of most, if not all, major sea powers of world history. Progress in nautical archaeology in the past few decades has brought about a much better understanding of shipbuilding traditions of the Indian Ocean, until then limited to textual and ethnographic sources. Only a few shipwreck sites and terrestrial sites with ship remains have been studied so far along the shores of the Red Sea, the Persian Gulf, or the Indian Ocean proper. Many more were found in recent excavations in the Southeast Asian seas, which were built along Southeast Asian or Indian Ocean shipbuilding traditions. Two main technical traditions can now be clearly identified for pre-modern times: the Arabo-Indian sewn-plank ships of the western Indian Ocean, which survived into our times, and the Southeast Asian vessels that evolved from a distinctive sewn-plank technology to fully doweled assemblages, as could still be observed in Indonesian vessels of the late 20th century. The still limited number of shipwrecks brought to light in the Indian Ocean as well as the considerable imbalance in archaeological research between the Indian Ocean proper and the Southeast Asian seas have hindered the advancement of the discipline. Considerable difficulties and interpretation problems have moreover been generated by biased commercial excavations and subsequent incomplete excavation records, not to speak of the ethical problems raised in the process. Such deficiencies still prevent solid conclusions being drawn on the development of regional shipbuilding traditions, and on the historical role of the ships and people who sailed along the essential Indian Ocean maritime networks.