We plan to do a day trip in September from Viena to Melk and then take the boat to Krems. I assume you can hop on and off these boats and catch the nest one? We would like to get off for a couple of hours in Durstein and then complete the trips to Krem and get a late train back to Vienna.
Should we book the train tickets ahead or can we get them the day of travel to be flexible with the time?
Any other advice for this trip?