Traveling smoke-free along the Rhine River

I too don't like smoking, and in the past decade found it was almost impossible to avoid sitting near smokers in European restaurants.

In recent years I have found that Europe (trains, restaurant, even accommodations) is almost entirely smoker free.

Smoking regulations vary among the single states. In the area covered by your trip (Baden-Württemberg, Rheinland-Pfalz and North Rhin - Westphalia) there is either a total ban of smoking in hotels and restaurants or there are kinds of "reservation" for smokers. You never will have to dine with smokers in the same room and all trains are smoking free.

You will probably still find smoking in outdoor cafes and the like.

"If we decide to go out on our own instead of a cruise we will need help knowing where to travel and what to see; as we have no idea..."

You've probably been drawn to the Rhine in the first place by images like those below - right?
https://www.uli-franke.de/wp-content/uploads/2014/07/20140622_144833-Burg-Rheinstein.jpg
https://upload.wikimedia.org/wikipedia/commons/4/4c/Bacharach_BW_9.JPG
http://www.bingen-ruedesheimer.de/wp-content/uploads/2012/10/LZ1B0487-als-Smart-Objekt-1.jpg
https://upload.wikimedia.org/wikipedia/commons/thumb/e/ed/Bopparderhamm1.JPG/1280px-Bopparderhamm1.JPG

This is the most scenic part of the river, the Upper Middle Rhine Valley, a 40-mile segment that lies south of Cologne, roughly between Koblenz and Bingen. It might require only a couple of hours on a sightseeing ship to cruise this part. Since the Rhine is 700+ miles long, I wouldn't expect the rest of it to look anything like this - and it does not. Much of it is pretty dull and flat. So I think you have a good idea about seeing the place on your own.

If anything on the Rhine is a must-see, it's the Middle Rhine Valley. Here's some area travel info. Click on "Romantic Rhine." But there's also a runner-up in the must-see category that's only a short detour from the Rhine. At that same page, click on The Moselle-Saar for travel info. The Mosel (as it's written in German) is a smaller, quieter, curvier river valley that makes for a great detour from the Rhine - it's also dotted with scenic, old-world villages and wine towns as well as a few castles.

Places to check into:
Cochem
Trier
Burg Eltz
Bernkastel

Trains are a really nice way to get around these two river valleys; day passes like the Rheinland-Pfalz Ticket are printed in German but can be bought using the English option from any DB ticket machine in Germany. The ticket covers the entire Rhine/Mosel region and costs around €30/day per couple. You get nearly unlimited access to area trains (and any connecting buses) you might need.

You can't go wrong with a stay of 4-7 days in the Rhine/Mosel region.

No idea how much time you might have, but a trip south along the Rhine from the NL to Basel also allows for visits to...
Cologne
Remagen (WW II site/museum)
Mainz
Heidelberg
The Black Forest and the Black Forest Railway
Freiburg

All these places are accessible by train as well.

I am particularly sensitive to smoke as well, but in the several years I lived in Germany within the past decade, I don't recall ever encountering smoke thick enough to bother me.

Smoke inside the restaurant building is against the law, but outdoors in a court yard is common. A river cruise is fine, but if sitting up top outside, then you are subject to smokers. The only way to avoid this is sit at the from of the ship or sit down below which is inside.

Hi Sandy, We spent 3 nights in Boppard last September and were not bothered by smokers at all. Of course we made sure the hotel was NON-SMOKING when making the reservation. And Russ gave very good advice above on places to visit along the Rhine and Mosel. One thing, a long river cruise may get boring . I personally tend to get antsy after several hours...
Have a great trip!!!

Smoking on our Avalon River Cruise was only on the very back deck outdoors on the ship. I would have a hard time choosing a river cruise as the way to see the Rhineland. They sail right past things that I would want to visit on a return visit there. I think for a river cruise to make sense you have to embrace experiencing that mode of travel as being your goal, and just let go of orienting around seeing a particular place. Unless you are lucky and can find a cruise that builds their journey around what happen to be your specific sightseeing goals.