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.
EV6 The Rivers Route
It usually runs along both sides of the Danube, though sometimes it runs only along one side so that you must cross the Danube a number of times during the course of the route. The Danube flows through very diverse landscapes, including mountainous terrain and passes through a few nature reserves. The route passes several mountains, towns and monasteries, artistic buildings and geological features. Where the current crosses great plains, the bike path often runs along high water dams with extensive views, beginning in Lower Bavarian, northern Austria (e.g. Marchfeld) and finally in Hungary.