I hope you're not still talking cruise ships here! Those folks are often paying high prices by the minute or by the megabyte for access: you'd be pretty literally stealing from your neighbors in that situation. (The moral issue for pay-by-the-day systems is one step further removed, but I think it's still real.)
In this context "access control" doesn't mean what you think it does. It refers to multiplexing the communications of multiple devices over a single shared communications medium, as in "controlling" (arbitrating) shared access to the radio spectrum. It has no relationship to network authorization or authentication and provides no security whatsoever.
Calling it "access control" has always been confusing which is why people started calling it Machine Address Code or Ethernet Hardware Address instead.
Regardless, the judge is going to look at intent and knowledge. You knew this was a paid service, and your intent was to not pay. You understood this was a way to avoid payment, and you understood that someone else had paid for access.
