boat trip from Worms to Koblenz Germany

Are you wanting a day cruise or an cruise with overnight accommodations.

a day trip

You might think about taking a train from Worms to Bingen (Rhein) Stadt and picking up the K-D boat there for a cruise to Koblenz.

Your best day cruise option would be to start in Bingen - where the scenery starts - and to continue at least to St. Goar (1.5 hours,) to Boppard (2.3 hours,) or to Braubach (home of Marksburg Castle, nearly 3 hours.) Use the trains before and after.

KD Schedule, 2014

While it's possible to start a cruise in Mainz and finish in Koblenz, that trip (with the KD line) would start at 9:45 in Mainz and end 18:10 in Koblenz with a 3-hour layover on the way. Uggh. The first 1.5 hours would be fairly dull. So would the last hour or so as you approach Koblenz. Also, the Mainz and Koblenz docks are a lengthy walk or bus ride from the train stations.

There's a dock for industrial traffic at Worms, but I don't think I've ever seen any kind of ferry traffic. As far as I know, the furtherest south upriver ferry traffic docks is in Mannheim.

There are docks for cruise "ships" in Basel, Switzerland.

I meant day excursion boats.