Austria-Hungary's river-warship problem

Austria-Hungary's Adriatic navy could reach the Mediterranean directly, while its Danube force would have to pass through other states to reach the sea. River warships had little room to evade an attack because their routes ran upstream or downstream. They needed enough power to overcome the current, with armour and firepower taking priority over additional speed. River width also limited a vessel's length and size because it had to be able to turn around. A modern comparison distinguishes azimuthing pods, which project below the hull and combine steering with propulsion, from manoeuvring thrusters at the sides or stern. The fixed thrusters in that comparison provide thrust in particular directions instead of rotating through 360 degrees. Such manoeuvring aids were unavailable to the early flotillas under discussion.