We are staying in Boppard (Thanks Russ for all of your info and advice) - will have 4 nights there - the first day we will spend in Boppard, day 2 going to take a train down the river and likely visit Sankt Goar and Oberwesel. Day 3 train to Bacharach then to Bingen and ride the KD Ship back north. Day 4 we are going to go to Koblenze to ride the cable car and have lunch at the Fortress/Castle Biergarten. The chairlift in Boppard is a hard no from the wife as we will have a daughter turning five on this trip with us.
Are there other towns worth stopping over on the train to see? Even if just an hour and grabbing abeer or wine until the next train arrives?
Options I see on google maps:
Bad Salzig
Hirzenach
Fellen
Trechtingshausen
Spay
or if any that are an easy ferry crossing across the river (close to train station, close to downtown area) - we are up for that as well
cheers