Let's break down why:
* Spoil ship: This phrase could mean several things:
* To damage a ship: This might happen due to storms, accidents, or intentional sabotage.
* To waste a ship's resources: This might involve misusing supplies or abandoning a valuable cargo.
* Porth: This is likely a misspelling of "port," which refers to a harbor or a place where ships dock.
* Tar: This is a thick, black substance used to waterproof ships' hulls and other wooden structures.
Possible Interpretations:
It's hard to say what the intended meaning of the phrase might be, but here are a few possibilities:
* A ship being damaged by tar: Perhaps the tar is being used improperly, leading to damage to the ship's hull.
* A ship being damaged while loading tar: The tar could be spilled or mishandled during the loading process, resulting in damage to the ship.
* A ship being destroyed in order to obtain tar: This is unlikely, as tar is relatively cheap and plentiful.
If you have more context or information about where you heard this phrase, it might be possible to make more sense of it.