I will be traveling in late September. I checked out the crossing I see 11am then it says "The ferry commutes up to and including 18:00" Then I see listing from 18:00 until 22.30 last ferry. Does this mean their are Ferries between 11:00 to 18:00 and they didn't want to bother typing the number for those hours, or am I out of luck for those hours? Thanks
Do you have a link for the listing you are looking at? Tough for us to know what it is you are reading without access to the site. Most of the ferries run into the evening/night though.
I think it is a case of "lost in translation". If you read it as "The ferry runs continuously until 18:00", then they list individual times after that, then it makes sense.
The word "pendeln" in German covers both meanings.
Here is the official website for the St. Goarshausen-St. Goar ferry. The schedule shows it running every 20 minutes all day long, including 11:00 to 18:00.
The part about between 11:00 and 18:00 refers to Samstag, Sonntag und Feiertag (Saturday, Sunday, and Holidays) when it runs "im Pendelverkehr". The website further goes on to define (according to Google translate) Pendelverkehr as:
the ferry has no fixed departure times
the ferry adapts to the traffic
the ferry is constantly going back and forth (analogous to the clock
pendulum); at least every 10 minutes