we will be staying in koblenz. we want to take the k&d boat up the mosel to cochem. is it possible to boat back same day? or do we need to take the train? next day, we want to go down the rhine to bachrach. can we boat back same day? or do we need to take the train? thank you, milobrew.
You can find all of these schedule at www.k-d.de.
Looks like the only boat leaves Koblenz at 9:45 and gets to Cochem at 15:00. The only boat back down leaves at 15:40 and gets back to Koblenz at 8 PM. It wouldn't give you any time to see Cochem. The boat trip is pretty slow and boring; I'd stay in Cochem longer and take the train back.
Better yet, take the train to Cochem and get the 20% discount for the boat trip back. The only problem with that is that you don't get back to Koblenz until 8 PM.
Koblenz to Bacharach is up the Rhein, against a very strong current.
There is a boat leaving Koblenz at 9:00, getting to Bacharach at 13:30 (1:30 PM) and a return boat leaving Bacharach at 15:15 and getting to Koblenz at 18:10. That would give you 1h45m to see Bacharach, enough time, IMO. Still, I think I would take the train up to Bacharach and come back on the boat.