Socialist Federal Republic of Yugoslavia
Regarding rivers, the Danube was navigable throughout its entire course in Yugoslavia, linking the ports of Belgrade, Novi Sad, and Vukovar with Central Europe and the Black sea. Long stretches of rivers Sava, Drava and Tisza were also navigable.
Danube
In the 19th century, the Danube was an important waterway but was, as "The Times" of London put it, "annually swept by ice that will lift a large ship out of the water or cut her in two as if she were a carrot."