Unprecedented flooding disrupted our Danube cruise on the Viking Odin and turned it into a bus tour. The flooding was an "Act of God" and affected all river traffic. Eventually, the German authorities closed the river to traffic and ended any speculation that we might sail (for even a part of the trip).
The Viking response was outstanding. The first night, they put us up in a first-class hotel in Budapest. Dinner and breakfast were included. After a city tour and lunch, we were transported by bus to Krems, Austria, where we boarded the Viking Freya, which was tied up in an industrial area (not very scenic). Nevertheless, the accommodations and hospitality on the boat were excellent. We toured by bus each day, as our cruise director, Stein, put a tour program together on the fly.
After 3 nights on the Freya and tours in Vienna and Melk (with optional activities provided at no cost - more to follow), we were transferred to the Viking Odin at Regensburg for 3 additional nights. The Odin was moored in an attractive location within walking distance of the city center. We saw most of the highlights we expected to find on this cruise (other than the scenic cruising), and Viking made up for this shortcoming by adding optional tours and activities for no additional charge, for example: Tour of Regensburg Castle, winery tour in Krems, concert in Vienna. In addition (while we probably didn't need it), Viking provided an open bar for two nights on the ship and (a surprise!) forgave all the bar bills when we checked out.
Finally, we just received a credit from Viking for 75% of the cost of our cruise (to be applied to a future Viking cruise within one year). I don't know how they could have treated us any better - under the circumstances. Thanks Viking! BTW, aside from a few rain showers, the weather was excellent - sunny and mild. I feel bad for the group that preceded us a week earlier when constant rain produced the flooding. One last note: If you spend the money to take the "Romantic Danube" cruise, spend a little more to take the 3-day extension in Prague. It was wonderful - and the full-time Viking people at the hotel were very helpful with tour information, dining reservations, etc.