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
Apart from a couple of secondary navigable branches, the only major navigable rivers linked to the Danube are the Drava, Sava and Tisa. In Serbia, a canal network also connects to the river; the network, known as the Danube–Tisa–Danube Canals, links sections downstream.