There were two kinds of vessels regularly operating during the season between Vienna and Bratislava on the Danube River: a hydrofoil and a speed catamaran. Now, only one is still in operation — the speed catamaran.
The hydrofoil, also known as the "rocket," was a technical landmark produced in the USSR. The rocket served for a long time; it was an indestructible and smoky Soviet machine. It passed through the locks at Freudenau, making the cruising time a bit longer.
Twincity liner is more modern and its advantage is that it leaves in Vienna right in the center nearby Stephenplatz.
More information - time tables, tickets:
Twin City Liner in Vienna: >>
Twin City Liner in Bratislava: >>