1 day on the Rhine

Best place to catch the boat? Bingen Stadtbahnhof (not Bingen Hbf). The part from Mainz down to Bingen is not that interesting. The part from Bacharach to St. Goar IS the most interesting if you can only do that segment, but a lot of pople like the Bingen to Bacharach section as well.

If you purchase the Rheinland-Pfalz-Ticket, it will get you to Bonn Hbf. You will still need a local ticket from Bonn to Köln. It might be less expensive to just use a QdL- or Schöne-Wochenende-Ticket the entire way. What day are you traveling? Two people?

The logistics make for a very long day.

ICE 372
Dep 08:13 BASEL SBB (Switzerland)
Arr 10:23 MANNHEIM HBF (Germany)
IC 2218
Dep 10:39 MANNHEIM HBF (Germany)
Arr 11:18 MAINZ HBF (Germany)
RE 25372
Dep 11:32 MAINZ HBF (Germany)
Arr 12:09 BINGEN(RHEIN) HBF (Germany)

KD Line River Boat
Shi 212
Dep 14:30 BINGEN(RHEIN) KD (Germany)
Arr 15:55 ST GOAR KD (Germany)

RE 25434
Dep 18:00 ST GOAR (Germany)
Arr 20:02 KOELN HBF (Germany)

The part from Bacharach to St. Goar is NOT the most interesting, it is simply a very short cruise where you only see 3 castles. Why Rick recommends such a short cruise is astounding and baffling.
Get on the ship at either Bingen or Rüdesheim, take it to St. Goar and you can see about 40 castles in under 2 hours.

There are Sparpreis tickets available now for 29.90 EUR for Basel Bad Bf to Bingen Stadt Bf. It is 10 EUR more if you go from Basel SBB.

Thanks for the help. Lee - there will be 2 of us travelling on Sept. 11th. What is the QdL- or Schöne-Wochenende-Ticket?
I'm also unfamiliar with the Sparpreis? Where can I find info/purchase?

Sept. 11 is a Monday so you cannot use the Happy Weekend (Schöne Wochenende) ticket.
In case you are traveling through Germany though on a Sat. or Sun. this ticket costs 40€, with each additional person costing 4€. It is valid for up to 5 people on all Regional trains, all day long.

The Quer Durch Deutschland ticket (All Through Germany) is a ticket valid on all regional trains in Germany, all day long for up to 5 people. One person pays 44€ and each additional person pays 8€. You have to wait until 09:00 to use it.

Considering your pack-it-all-in plans, David has provided you with a reasonable train schedule for your day. It puts you on high-speed trains between Basel and Mainz (IC, ICE) and you get to Bingen at 12:09 for lunch prior to your 14:30 cruise.

The QdL ticket day pass can be a good value for some trips, but using it would mean a very delayed arrival in Bingen Rhein Hbf at 15:56 since you must use the slow trains with this day pass and since you must leave after 9 am.

"I'm also unfamiliar with the Sparpreis? Where can I find info/purchase?"
Information: https://www.bahn.com/en/view/offers/germany/saver-fare.shtml
Purchase is done from the DB itinerary page; enter your data and search: http://reiseauskunft.bahn.de/bin/query.exe/en

I just searched David's schedule for Basel-Cologne on Set. 11 and found a price of €139.80 for two at DB. You can find it too if you enter two stopovers - enter a 2-hour stopover in Bingen and a second 2-hour stopover in St. Goar. (Note that your ticket includes a train segment between Bingen and st. Goar that you are not using because of the cruise, but that's OK.)

A second option appears as well, priced at only €79.80. Leave Basel at 9:13, arrive Bingen Rhein Hbf at 13:34; take your 14:30 cruise, do Rheinfels, etc. and you still reach Cologne at 20:02.

Either plan works depending on your preferences but... What about your luggage? You have two potential luggage problems, one in Bingen and one in St. Goar...

Bingen: If you are packing the way Rick Steves tells you to pack, it is possible to use either schedule above and walk between Bingen Rhein Hbf and the KD dock for your cruise. If you can't walk for 15 minutes with your bags, you will need a taxi, or you will need to do as Lee suggests and use the Bingen Rhein Stadt station instead (which involves a shorter and less complicated walk.) You can use the Stadt station with either the 8:13 departure from Basel or the 9:13. With the 8:13, just get off the train at the Stadt station at 12:01 (instead of 12:09 at the Hbf station.) With the 9:13 schedule, get off at the Stadt station at 13:31 (instead of the Hbf station at 13:34.)

St. Goar: You probably don't want to hike up the hill to Rheinfels with your bags. There are no lockers at the station but the TI office will hold your bags for you. See their hours here:

https://www.st-goar.de/18-1-tourist-info.html

IMO your itinerary for this day is overpacked with travle and misguided. I would spend the night either in Bingen (drop bags at hotel there, and cruise bag-free) or in St. Goar right after the cruise. Then continue your journey the following day to A'dam, making a stopover in Cologne on the way (Cologne station has a baggage storage system which makes this simpler.) St. Goar is a lovely town with the most scenic setting on the Rhine. Love that view across the river.

https://farm4.staticflickr.com/3734/8921199351_dc4bb7f642_o.jpg

A second option appears as well, priced at only €79.80. Leave Basel at 9:13, arrive Bingen Rhein Hbf at 13:34; take your 14:30 cruise, do Rheinfels, etc. and you still reach Cologne at 20:02.

If you buy the ticket to leave from Basel Bad Bf, which is about 2 km from the main Basel SBB station, then the price is 59.80 EUR. That is because Basel Bad Bf is considered a "German" railway station. They are connected by rail and city tram lines, and if you are staying on the north side of Basel, will be the closest station. If arriving from elsewhere in Switzerland, ticket yourself to Basel Bad Bf.

The big price difference is because a ticket to Germany from Basel Bad (actually Basel Badischer) station is considered a domestic train ticket, while from Basel SBB station is considered an international train ticket.

Thanks all. I really appreciate the help. We ended up making some adjustments to our itinerary based on some of your feedback.

Sunday we'll be travelling from Bern to Cologne via ICE
Rhine cruise on Monday from Cologne
Tuesday Cologne to A'dam
Later that week Friday A'dam to Dusseldorf & Saturday as well.

For the travel on trains in Germany is there a pass (flexi) that would be beneficial or just point to point tickets?

I think you might find Rhine cruises from Cologne a tad disappointing. The only point of note is the old bridge abutments at Remagen where the American Army found an un-destroyed railroad bridge and were able to cross the Rhine in 1945. And a magnificent oil refinery between Cologne and Bonn.

Sunday we'll be travelling from Bern to Cologne via ICE
Rhine cruise on Monday from Cologne

As said above, many people prefer the Rhine cruise from Bingen to St. Goar or Boppard. Leaving Bern in the morning (8:04, IC 960) you could arrive ad Bingen Stadt by 13:31 and catch the northbound boat departing 14:30 (there is another one at 16:30), which will arrive at St Goar 15:55 / Boppard 16:50. Then you could continue your trip by train to Köln.

Personally, I'd prefer to spend the night in either St. Goar or Boppard and spent half a day in Köln. The cheapest way to do that would be to book two saver fare ticket at the DB website, one from Bern to Bingen Stadt (today's price is 39.90) and another from St. Goar to Amsterdam (requesting an intermediate stop in Köln of 4 or 5 hours; today's price is 34.90).

Personally, I'd prefer to spend the night in either St. Goar or Boppard and to do a a half day in Köln.

This! For the reasons at least two people mention above.