Best of Rhine and Mosel regions in 3 days

"1st full day - no alarm clock, get used to their schedule and we'd be good for some walking/hiking/exploring of the local towns"
That works. Maybe visit Bacharach and/or Oberwesel, both just south of St. Goar.

"From other posts, I have seen recommendations to take the KD boat from Bingen to St. Goar, spend a couple of hours there and then take the train to Braubach to see Marksburg Castle. Is that all day right there?"

Pretty much. You should have time for a short lunch in St. Goar and should be able to spend the evening in Boppard. Note that there is no direct train between St. Goar and Braubach, which lie on opposite river banks. The simplest route is to take the ferry to St. Goarshausen (takes a few minutes, runs all day long between St. Goar and St. Goarshausen) then walk north to the St. G'hausen station and catch the train to Braubach (a 22-min. train ride. Alternatively, take a train from St. Goar to Koblenz and another to Braubach.) There's normally a 4:00 pm English tour at Marksburg.

Once finished in Braubach, return to Boppard using a northbound train to Koblenz (11 min.) + a train from there to Boppard (15 min.) It's also possible to take a train SOUTH to Filsen (about 7 minutes) then walk south along the river (probably 10 min. or so) to the ferry crossing for Boppard.

"I'm also confused about the Mosel area... Is the section of the Mosel between Cochem and Koblenz nice?"

It's pleasant. But there isn't much demand for this stretch of the river (KD has only 3 boats per week, 1 per day Fri - Sun) since it lacks the dramatic sights of the Rhine and requires 5+ hours from Koblenz to Cochem. You can enjoy the Mosel scenery quite nicely from the window of your train - the tracks follow the riverbank all the way to Cochem - and from Koblenz to Cochem it takes only about 40 minutes. And you can do this at any hour on any day of the week.

Walking: There is a nice trail you can take from the top of the chairlift ride in Boppard to Gedeonseck and Vierseenblick lookouts for cool views of the river. On this map, the chairlift is in blue, the trail (and other area trails, including the Weinlagenweg through vineyards near the river) in red:

Boppard hiking map

Gedeonseck terrace-restaurant is a scenic spot for some refreshments:

gedeonseck

The lower Mosel is easy to explore by train. Get a VRM Minigroup day ticket and you can use the train for hop-on-hop-off. The trains run every hour in each direction. The rail line moves away from the river after Bullay, and also leaves the VRM district of ticket validity. There is a bike trail/walking path along the river in an old railroad bed. The ticket is good starting in Oberwesel and north. http://www.vrminfo.de/en/home/
Because there are a lot of locks in the Mosel, cruise boats take a lot of time to get through the area. There are a few boats out of Cochem, http://www.ferienland-cochem.de/nextshopcms/show.asp?lang=en&e1=136&ssid=1
And if its the weekend in the fall, some of the towns will have "strassenweinfesten", street wine festivals with bands and wine.

Thank you so much, this is just what I needed. I did find a short boat tour from Cochem on the Kolb Brothers boat website here:
http://www.moselrundfahrten.de/en/schedules-region.php?filter=Cochem&bereich=Cochem

"Moselle round trip on the loveliest part of the Moselle
The excursion begins at the dock near the old Moselle bridge and continues downriver to the Cochem leisure center. Then the journey upriver begins, offering extensive opportunity for enjoying the romantic Moselle landscape in peace and quiet.
The journey continues past Cochem with Reichsburg Castle towering over the river, past the Cond and Sehl districts, the Brauselayfelsen (Moselle Loreley), Ebernach Monastery, the wine villages of Valwig and Ernst, surrounded by vineyards.
detailed commentary makes the excursion an unforgettable experience."

Does this make sense? Looks like it's only an hour round trip from Cochem with many departure times.

I've been up the Rhine three times over the years by rental car.

My stops are in Cologne, in Koblenz at the Konisbacher brewery beer garden (overlooking The Rhine) and in Bacharach to spend the night in a quiet little city.

Bavaria Ben covers this region very well in his website--including many great bed and breakfasts. I refer you to him.

Yes, Kolb Bros is the company that runs boats out of Cochem. Go for it.

If it rains, do what every other tourist does when it rains - put on your rain parka, and go into the stuffy cabin of the boat. You said yourself you have three specific days to see two rivers, and you have to make the best of it. Some years, I dragged rubbers along in my suitcase.

If you don't care to see Burg Eltz, don't go. I think Rick overstates how swell it is, especially the modern furnishings of the real people who live there - a mansion interior rather than a castle. I think it's missable, but few agree with me.

We enjoyed a day in Traben-Trarbach, which saved a lot of moving around. It has a very low-impact but high view point. Also a nice multi-vineyard walk that leads up to a winery with (paid) tastings at a cafe where you can have lunch. People who want to visit wineries instead might go to Bernkastel-Kues, but you must make appointments at any winery you've ever heard the name of. Otherwise they'll turn you away.

We also stayed in Mulheim, but with a car. As others noted, the Mosel is very different, and maybe slightly less dramatic than the Rhine. Don't try to go too far along it on your tight schedule. Although we didn't walk to Burg Eltz, I've never read a post from anyone who didn't like the walk from the train station. It is very picturesque, except when they have scaffolding up. But that happens in cities, too, doesn't it?

I'd skip the Mosel by boat. If you boat the Rhine, the experience will be essentially the same (but mostly views of hillsides with vinyards).

For the Mosel day, start by training all the way to Trier (I'd suggest starting early). The town is nice but see the Roman ruins beginning with the Black Gate right as you enter town - some of the best Roman ruins outside of Italy. After a few hours to look around, train to Moselkern. From the station hike through the forest to Burg Eltz and tour there - I don't disagree that the castle is missable but the walk through the woods is more than half of the experience (the natural beauty/hike you mentioned). Don't wait a long time to get an English tour, just take the first tour (fairly brief tour anyway) and get an English brochure that describes essentially the same thing. Walk back to Moselkern through the forest and either train to Cochem for a look around/Weinstube or head back to your lodging for the night. My recommendation would be to stay in Cochem one night and plan to eat an unhurried dinner at a Weinstube.

Next morning, get up and head to Boppard - tour the Rhine as you described from Boppard including the KD boat and Marksburg. I also love the Rheinfels castle ruins. It's a completely different experience from either Burg Eltz or Marksburg. Get there early and you have the place almost completely to yourself.

Be sure to take advantage of the group passes on the regional trains, they're a great bargain for hop-on, hop-off touring of the area.

This is all fabulous, thank you. It sounds like there isn't much on the Mosel between Koblenz and Cochem, then - other than Burg Eltz? So if we want to look at the Mosel by train we go south from Cochem?

If you search this forum, you'll see that many people take the KD boat from Bingen to Boppard and leave it at that. If you are sleeping in Boppard, you don't even need to waste the small amount of time it takes for the second train. And you get a KD discount with the first train's ticket, to Bingen.

You cannot rely on *one** person's opinion, but based on what you've written (which includes my perception of invisible Internet *affect** ...) you can skip the Mosel, especially if you're going to Cologne (rest of itinerary not mentioned or referred to) because there are Roman artifacts there. Trier does have a very nice amphitheater, as well as the Porta Nigra and museum. But the Cologne Greco Roman museum is a world landmark.

You mentioned light trail walking, but you're not showing much interest in the proposed walks. There is plenty of (paved) walking in Koblenz and Cologne.

We're on our last night of 3 in Zell on the Mosel. We spent nearly a full day traveling to/from and seeing Trier. Maybe we've seen enough in our few visits to Europe, but we could have easily skipped Trier and spent the time elsewhere on the beautiful, relaxing Mosel (definitely not including tour bus central Cochem. Cochem is for new travelers. I don't mean to sound a snob, but we found Cochem centered around shopping. We liked the Rhine very much and felt Bacharach to be the most charming followed by st. Goar. We saw Burg Eltz and agree with the comment not to wait for an English tour. As far as Burg Eltz, we walked the path in and the road out (weather was cooperative). The Hubbs quite enjoyed the quality of the structure for the medieval time period. Glad we had the chance to see it. Although we didn't go to the Marksburg, this might be more convenient for you to see and also cover the historical period. Personally, we really enjoyed the more country, less touristy, part of the Mosel. But there is more to see and do on the Rhine. Perhaps save the Mosel for a return trip. Bacharach will give you the flavor of Beilstein. Spend the downtime of skipping the Mosel by enjoying a slow glass or two of wine with a German meal.

I agree with Kay about Cochem...it does seem to center around shopping and, as I biked through it once, I counted 33 tour buses in the parking lot right there along the river. But I do love the other small towns along the Mosel, and I quite enjoyed several hours walking around Trier to see the Roman ruins.

We hiked to Burg Eltz and took a tour last Thursday and enjoyed it very much. Nice walk and if you want, you can take a taxi back to the train station. You must call ahead for one, though.

St. Goar is very pleasant and you can take a short hike up to Rheinfels castle. Beautiful views!

Just got back from Europe - spent 4 nights in Koblenz and had a hard time deciding how to see the small towns on the South side of the Mosel. I decided to skip the boats for the most part because they take too much time. I had a rail pass so I took trains every day - first to Trier, then up the Rhine to Cologne ( spend 1 hour there seeing the Dom - it's fabulous) and Bonn plus the hike to Burg Eltz. Another day I trained to Bulley and then to Traben Trarbach and then boat to Bernkastle-Kues, where I spent a delightful hour in the wine cellar of the wine museum with 140 wines, all of which I could have tasted for only 18 Euros. I also rented a bike for part of one day - out of Cochem. I went to an orchestra concert in Bonn that evening. I took a boat tour on the Rhine on my first European trip - it's a very popular trip. I did it from Bacharach to Koblenz - make sure you do it downriver (northbound) to save time. Good luck.