Happy STS! :)
What is the biggest region in your world? How does it interact with the rest of the world (in any way, politics, geographically, cultural exchanges, etc.)?
Have fun! :)
Hi! Thank you so much for the ask!! :3
Based on my map I think the Restless Sea would be the biggest region. Which being the central sea between the continents, all ships must cross it to get to other regions. That isn't really an issue along the coasts, but there's a reason it's called the Restless Sea.
There are tales of giant sea monsters roaming the deepest parts of the sea. Many ships tried to cross directly from Amiadin to Brariheba never returned, so most stick along the coasts. I'm sure there's laws in place for how close a ship can pass a foreign coast, but most of the sea isn't controlled by one kingdom.