system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 why ships don't use left, right, front, and back.

I assume it's so sailors can insult the Lilly livers land lovers.
gpt
Originally, ships had a "larboard" and a "starboard". The "starboard" meant literally the side where the steering paddle was located -- compare German "Steuerbord", where "Steuer" means "steering".

This is because early Germanic ships had the steering paddle on that side. The other side was the side used for loading and unloading, and was originally called "larboard" -- "loading side". That would get confused with "starboard", though, so it was later replaced with "port", meaning the side of the ship facing port when docked.

So that's port and starboard for you: the loading side and the steering side.

"Bow" is an old word that originally meant an animal's shoulders, so where the sides of the ship curved at the front was considered to be the ship's "shoulders". It's not clear where "stern" comes from, but it may be again related to steering, since the steering rudder was not only on the right side of the ship, but also at the back. But that's conjecture -- nobody seems to know for sure.

Why don't they use the normal English words? Well... why should they? It may be that some sailors centuries ago literally didn't know their left from their right, but they knew damn well which side of the ship was the loading side.