Danube
The Danube flows through many cities, including four national capitals (shown below in bold), more than any other river in the world. Ordered from the source to the mouth they are:
The Danube is navigable by ocean ships from the Black Sea to Brăila in Romania and by river ships to Kelheim, Bavaria, Germany; smaller craft can navigate further upstream to Ulm, Württemberg, Germany. About 60 of its tributaries are also navigable.
New Danube
The New Danube can be reached via U-Bahn lines U6 (Neue Donau station), U1 (Donauinsel station) and U2 (Donaustadtbrücke station), via tram line 31 across the Floridsdorf Bridge, and via various city bus lines. It has stretches suitable for regattas—in September 2009 the World Rowing Masters Regatta took place there—and a waterski lift. The best known stretch of shoreline is the Copa Cagrana, next to the Reichsbrücke. Private motorboats are not permitted on the New Danube.