I remember one of my elementary school teachers telling us that on ships, the left side was called port because it was the side towards the port – ships docked on that side – and the right side was called starboard because, as it was away from the port, you could see the stars. In my adult years I have come to realize that many teachers, like many other adults, will often make things up that seem reasonable to them and assert them as fact when explaining things to children. This is one such instance. Actually, the star in this word comes from the word that, on its own, came to be steer in modern English. Old Germanic ships were steered by a steersman who stood on the right side of the vessel with a paddle. (This did force the ship to dock on the left side, so port is port because that’s the side of the ship that had the port – opening – in it for loading and unloading; that side was originally called the larboard.)
But no one thinks of steer now when seeing this word. Steering is not done from the right side and hasn’t been for a long time. And star, well, star is star! It has that éclat that lends fulgurance even to such a baleful thing as a star-chamber. In this word, it is joined to board, which has that rigidity with the hint or threat of splinter, and so you can get a taste of a wooden ship at night, stars above and boards below. Try to ignore the rats running off the left side… the ship is broad and you’re on the right. No mixed-up road brats – or bastard – will steer you wrong. Hard a-starboard!
P.S. There’s a huge amount of etymological rubbish focused on things nautical and naval. Quite a few terms and phrases have baseless – and sometimes breathtakingly inane – stories about nautical origins circulating. Among the most senseless is the assertion that “cold enough to freeze the balls off a brass monkey” was a reference to cannon balls being stacked on brass plates on a ship’s deck. Whoever made this up knows not enough about a) ships in general, b) naval battles in specific, c) physics, and d) metal. Actually, it came from a host of phrases referring to brass monkeys, the first recorded one being “hot enough to melt the nose off a brass monkey.” (See www.worldwidewords.org/qa/qa-bra1.htm for more details.) Another common fase etymology is for posh, which has for decades been said to stand for “port outward, starboard home.” This is baseless. The term most likely comes from London street slang for “money.” See www.worldwidewords.org/qa/qa-pos1.htm for more details.