See this interactive MAP for the relative locations of the dock, the Vorgartenstrasse Ubahn station, about a 15 minute walk, and St. Stephan's Catherdral. the center of the city. Check with the PD or reception on how to use the Ubahn. It is an honor type system, where you validate your ticket in a machine on the platform. It is an easy and clean system. The ship apparently docks at 6:30, so you might have to skip dinner on the ship to get much touring in. Apparently you have a full day in Vienna. When we took thgis trip in 2009, we left the morning after arrival. This was OK with us, as we had been to Vienna before. As I remember it, it was about a half hour to the airport. We would be glad to answer any other questions about the trip.