36 hours in Bacharach?

The boat can actually lull the sleep-deprived into a slumber. I'd hate to see anyone sleep through this most scenic area. You'll want to stay a little more active on Day 1, probably. After dropping bags in Bacharach and getting lunch, I suggest you take a walk around Bacharach and/or catch the train to Oberwesel (5 minutes north) for a walk around the old town wall fortifications and this very handsome town:

https://www.tripadvisor.com/Attraction_Review-g198501-d2189241-Reviews-City_Fortifications-Oberwesel_Rhineland_Palatinate.html

The next day... do your cruise. But do some sightseeing first... I suggest you catch an early train to St. Goar for a morning tour of Rheinfels Castle. The best cruise segment, Bingen or Rüdesheim > St. Goar or St. Goarshausen, does not begin in Bacharach, unfortunately for Bacharach-dwellers. As you can see from the map, these town pairs lie right across from each other across the river. Rüdesheim is much more interesting than Bingen when it comes to sightseeing - so after your Rheinfels tour, I suggest you use the St. Goar > St. Goarshausen ferry crossing + the train to Rüdesheim. You'll probably arrive in R'heim around lunch time. At 16:15, the KD Goethe Paddlewheel steamer leaves for St. Goar (ar. 17:55.) So before your cruise you'll have maybe 3+ hours in R'heim for whatever - the cable car lift, a stroll around town, some of R'heim's sights, a meal. Then get to the dock. (Show your train ticket there to get a 20% discount on cruise fares.)

After you step off the boat in St. Goar, you could have dinner there - some restaurants there offer views of what is truly the best scenery in the Rhine Gorge. The Landgraf in the hotel next to Rheinfels Castle is nice but so are several down by the waterfront.

Bacharach of course has in-town restaurants as well but don't expect views like St. Goar's. It's 10 minutes by train from St. Goar back to your Bacharach base.

I've been there 4 times. Bacharach is a lovely place, but its a small place. You can walk leisurely from one end to the other in 15 minutes (stopping along the way). That is, its a place to be, and admire, but doesnt have a lot "to do". The castle at the top of the hill is an ambitious climb with a great view, but its an operating hostel, and not open for visitors. Nice restaurants and shops, and a perfect place to unwind from travel. So enjoy it, but don't expect more of it. A cruise is the main thing to do. If not enough, you can take the ferry over to other towns.

I agree that a cruise will lull drowsy travelers into sleep, and you don’t wanna miss it by sleeping through it. Save it for when you’re feeling most awake. Bacharach is quiet and cute, which makes staying awake a challenge. But it will be easier to explore in your jet lagged state than a bigger city. You’ll have a couple days to take it easy, so you’ll be nice and relaxed to kick off your vacation.

As for itinerary suggestions, I went to Germany the last two weeks of July 2019. I spent my last two nights in Bacharach, so didn’t have jet lag considerations anymore, but I was ready for the more relaxing pace of Bacharach. My vacation had been getting hotter and hotter. I was just under 90F in Munich in a hotel with no AC. It was even hotter in Bacharach. I arrived around 4pm, got settled in my room and took the earliest seating at Stuebers restaurant (no AC), then napped until about 30 minutes before sunset (I actually looked up the time of sunset). That gave me time to wander around Bacharach as weather was cooling. The next day I wanted to hike to Burg Eltz, as described in the RS guidebook. I was worried because it was so hot, so I woke up earlier than comfortable to arrive at Burg Eltz as soon as it opened. Train to Koblenz, change to train to Moselkern, hike. The hike was my favorite part of the Bacharach portion of my trip. I loved the castle too. After the castle, I had lunch in Koblenz (I had a pretty long wait before next train to St Goar). In St Goar I climbed up the hill to Burg Rheinfels. It was oppressively hot, but I had water and survived. My visit to Rheinfels was short, but I think your young boys will like it. Then I took a boat cruise back to Bacharach, dinner, and sleep before heading to Frankfurt airport the next morning!

With your schedule, I would assess how tired I am when I arrive in Bacharach. How much sleep did I get on the plane? How long did the train ride take? Is my room ready? I might have the energy to take the train to St Goar and see Burg Rheinfels. But I might be too sleepy, so I’ll wander around town until room is ready, then I can nap until dinner. Once fed, I might be awake enough for the last river cruise (downstream to St Goar, then train back), but I might feel better leaving that ‘til tomorrow. Next day I’ve got an alarm set to force myself awake early. There’s some time for a few zzz’s on the train, then the walk to Burg Eltz will let me breathe the fresh air of morning, so I’ll be awake enough to enjoy that tour, and I’ll have an entire day to explore the rest of the Rheinland. I can take the river cruise upstream back to Bacharach. I can wander around Bacharach, or I can sleep some more, so I have more energy for the rest of my vacation, wherever that may take me.

Have a great trip!

Thanks so much everyone. This is super helpful. This will be my 2nd time in Bacharach. My first time was in 1996 on my first trip to Europe where we went 'back door" style and had a budget of $30 a day!