Travelling by sea in the medieval Mediterranean was associated with many risks and dangers. Journeys were long, heavy storms or pirates lurked and in a worst-case scenario the ship was wrecked. A shipwreck could give rise to disputes and conflicts amongst various parties. The Byzantine legislator had to deal with these conflicts. What happened to the goods of the wrecked ship? Who was considered owner of these goods? How was the situation complicated when the ship was of foreign origin and what role did customs play in resolving these issues? In this paper I will attempt to highlight shipwreck and salvage questions in Byzantine legislation and practice. Aside from the traditional Byzantine legal sources, examples from treaties between Byzantium and the Italian city-republics will be examined from the eleventh and twelfth centuries.