Just returned from doing the Viking Spirit Vienna to Amsterdam cruise about 4 hours ago. Here is a quick update for those wondering what's going on at least for the ports on that itinerary (before I fall asleep).
We arrived Sat Sept 14 in Vienna and met the Viking Pride (not the Spirit). Due to low water levels around Passau, we spent 3 nights on the Pride and sailed as planed to Passau. Itinerary was kept, just different ship. (They are identical ships). On the 3rd day, they bussed us to Passau, had our time there, then we took a 3.5 hour bus ride with one 0.5 hour stop and then we boarded the Spirit. At this point, we were told the remainder of the cruise would go as scheduled.
We were on the Spirit for another 7 days when they finally told us the plans for the rest of the trip were being changed. As we neared Mainz, we were told the water on the Rhine was too low, so they diverted us to Frankfurt. We stayed in port there for the next 2 days. We took buses to Mainz and had free time in Frankfurt (Frankfurt is not on original itinerary). Following day they bused us to Rudeshiem, where we were able to board a small vessel (at Viking Expense) to at least cruise the pretty portion of the Rhine for 4 hours before being able to spend another 3 hours in Rudesheim. The buses here took about 2 hours there and 1 hour back.
Thursday when we should have seen Cologne and then Amsterdam, were basically missed. The majority of people were bussed from Frankfurt to Amsterdam (total of 7 hours) with a short stop in Cologne to see the Cathedral, lunch, then the remainder of the bus ride. Some of us took the Express train at our own expense which only took 4 hours, so arrived Amsterdam around 11:00 AM. Had the whole day at leisure before meeting up with Viking crew at 6 for dinner and a late evening Canal cruise.
Hope this helps those who are wondering what the water levels are and what Viking is doing at least on this itinerary. Will try to post more when I catch up on some sleep. ;-)