> 4.24 Coastal areas are areas that contain both land and water and
> can trace back a path, strictly over water, to an open sea zone.
> The exceptions to this would be regions that border the Caspian
> or Arial Seas (Caucasus, Dihistan, Lesser Armenia, Media,
> Hecatompylos, Nisa, and Chorasmia)

I think the terrority list is for an earlier version of the map - it needs to include:
Caspian: Alani, Ustiurt, Nalchik
Arial (Aral?): Sogdiana

However, this feels too "special case" for the rules. How about this instead?
4.24 Coastal areas are areas that contain both land and water
and can trace back a path, strictly over water, to an
area which has a water-only boundary.

That would remove the special-case listing of specific areas, but would make the Aral sea *not* coastal.

4.24 Coastal areas are areas that contain both land and water
and can trace back a path, strictly over water, to an
area which has a water-only boundary. Areas which have a
water boundary on a map-edge are considered coastal as well.

That would include the Aral sea, but would cause one problem. The area labled "Eastern Himalaya" has a small tiny lake which in split on the map edge, meaning it would be coastal as well.

Coastal vs not-coastal has effects on using ships (which aren't needed on the Aral - but could spend down treasury), or city sites which are vulnerable to piracy. The two areas are a 4 and 2 neither which are natural city sites. The 4 would be horribly inefficent to use as a wilderness city and the 2 borders a zero-pop and would be barbarian bait. I'm thinking that making the Aral non-coastal isn't a great loss.

My suggestion:
4.24 Coastal areas are areas that contain both land and water
and can trace back a path, strictly over water, to an
area which has a water-only boundary.

Agreed! Something with an example would probably help like:

4.24 Coastal areas are areas that contain both land and water
and can trace back a path, strictly over water, to an
area which has a water-only boundary (such as the Caspian Sea).