system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How ancient sailors could navigate to a specific port?

How sailor going from Venice to Athens in the ancient time knew to navigate EXCTALY to the port location?

I can understand general direction by stars or even a compass but to navigate to a very specific location is other problem as I see it.

I did some foot navigation and to get to a specific point of very different then a general direction and you can't use just general direction. If you miss your journey even in 0.5 degree you will get in totally other coast and not to the port you aimed for.

It will be even a bigger problem on the ocean travels. The Portuguese ships going to South America. How the know to land exactly at the port of Mexico or other places.
gpt
Venice to Athens is pretty easy since they would've had the shore in view all the time. They had maps and many landmarks to figure out their position.

For ocean travels, you only need to be accurate enough to hit the correct continent and then continue along the shore to your destination.