> The ferry is actually a very odd boat in this, btw. As I am not clear that starboard/port are fixed. The boat literally goes in both directions, such that I'm assuming I don't have to know which is the "front" of it irrespective of the direction it is currently traveling.

From what I understand, on ferries (and similar "two-sided" working boats), port and starboard get switched around when the boat changes direction of travel, usually when docked (and its navigation lights also turn from green to red and vice-versa).