MS Jan Heweliusz was a Norwegian-built Polish ferry named after astronomer Johannes Hevelius (Polish: Jan Heweliusz) that served on the route Ystad-Świnoujście. It was built in Norway in 1977 and was owned by Polish Ocean Lines and operated by its subsidiary company Euroafrica Shipping Lines. In the early hours of 14 January 1993 it capsized and sank in 27 metres of water off Cape Arcona on the coast of Rügen in the Baltic Sea while sailing toward Ystad with 64 passengers and crew. The accident claimed the lives of 20 crewmen and 35 passengers. 10 bodies were never found. Nine people were rescued. The sinking of Jan Heweliusz is the most deadly peacetime maritime disaster involving a Polish ship.