[Cronos]

Any examples of this for
1. Egyptians pre-Assyrian conquest
2. Roman Empire pre-476 AD

I put those specific dates :)

I have not seen any evidence of blue-water capabilities in either of those cases, so I’d like to know if you have

[SunkenCiv]

Mariners didn't hug the coasts, they still don't. Coast-hugging means elevated exposure to shoals, and was learned early. Routes no doubt got learned the hard way, and then as now the main threats were violent storms (especially at night) and piracy.

Fishing, which seems likely as the origin of exploration and migrations by sea, is prehistoric. Based on geology, Flores Island hasn't been part of the mainland for millions of years, even during glaciations, and yet 800K old artifacts were found there.