I guess I had better figure out how to upload a dev log or something with images to demonstrate what I'm talking about in the rules, since it seems like some people are having trouble understanding how the game works.
Oops! Yes, one the ending edges should be a starting edge. I had originally meant the bottom edge to be the starting edge, but I don't think it actually matters which is which.
I don't love the idea of the Sea Beasts. Keeping players in the game is nice, but that's some really, really heavy Kingmaker (i.e. the dead players have a huge amount of control over who wins the game, as long as it isn't them.)