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.
Chain boat navigation
However, fast currents when rivers were in spate could also be problematic for chain boats. Depending on the nature of the river bed, strong movements of sediment could lead to ements to aggradation, thus covering the chain with gravel and stones. A river bed with lots of ledges or large boulders – such as on some sections of the Danube – caused the chain to become snagged and was a major hindrance to chain boats.