“Vessels with bilateral symmetry have left and right halves which are mirror images of each other. One asymmetric feature is where access to a boat, ship, or aircraft is at the side, it is usually only on the port side (hence the name)”
Port makes sense, never thought about it. Ships I see rarely, so I couldn't tell which side they use (or even both depending on the harbor) But for passenger planes it's definitely left.
In German starboard is steuerbord, steuern = to steer. No shifting over the centuries.
However, port is still backbord. I am not familiar with Northern dialects (where they have a coast), back does not tell me anything. Maybe packen = to pack/load)??? Interestingly enough the English argument that the 2 words should not be too similar has not been applied. Maybe because there are already 3 vs. 2 syllables? Whereas English had 2 and 2 so they changed to 2 vs. 1 to make it make obvious what was said even in a big storm?
Similarly, the Danish terms are »styrbord« and »bagbord«, respectively. »Bagbord« comes from »bag« (back) meaning the backside of the sailor steering the boat, because they would be facing the steering side (»styrbord«; »styr« still means to steer today).
Starboard => Means "steering side of the boat" (b/c the oar was on the right side due to sailors mostly being right handed)
Port => The side that faces the port when docked