Many years ago an elderly couple drove from Wolverhampton to Plymouth to catch the ro-ro ferry to Santander; their first excursion abroad.
They carefully followed the signs to the ferries, and joined a queue of cars.
Shortly afterwards they were waved on to the ferry; and a few minutes later it set off.
When someone knocked on the car window and asked for the fare, they were quite indignant when it was explained that they would be in Cornwall in about 3 minutes and not Santander in 24 hours.