Rhine boat trip

By far the most interestion part of the Rhein is the "middle Rhine gorge", between Mainz and Koblenz, including St. Goar. There are regularly scheduled boats. Find the schedules at www.k-d.de. The boats don't go very fast. You won't get to see very much in a day if you do round trip. Best to take the boat DOWN (in the direction Mainz to Koeln) the river and come back on the train.

The Rick Steves Germany book has a several page description of this, with all the things to see and kilometer posts to relate it all to. Far too much to put into these messages. Can I suggest that you have a read and a study and then if you have any specific questions we can have a go at them...

Lee has it right. Cruise downstream (north) and return by train to make best use of your time. Here's a basic plan. Although it is possible to cruise from Mainz to Koblenz, this takes 5.5 hours and includes too much dull scenery. Bingen or Rüdesheim (opposite Bingen) are where the scenery becomes dramatic and the best places to get on the boat; from there, cruise north to Boppard (2.5 hours) or Braubach (3 hours.) Braubach is home to must-see Marksburg Castle: www.marksburg.de After Braubach, it is not especially scenic as you approach Koblenz, and Koblenz's boat dock is a long walk to the station, so by boat, Braubach or Boppard are best for ending your cruise. Once you've gotten off and looked around either Braubach or Boppard, you'll probably want to see one or two of the villages you cruised past; most of the interesting ones are on the "left" or west bank. St. Goar, Oberwesel, Bacharach, and of course Boppard are probably the best choices. Trains head south from Boppard hourly or better. If you're in Braubach, catch a train north to Koblenz (12 min.) then change for a southbound train to Boppard and the other villages. A Rheinland-Pfalz daypass (24 Euros for 2) covers trains if you aren't using a railpass day: http://www.vrminfo.de/en/tickets-and-fares/ticket-offers/rheinland-pfalz-ticket/ Boats: www.k-d.de