Is it impossible to win if the Galleon dies?

I built a new town on the coast to build another, but this doesn't seem to even be possible. I tried going around north, but the passage is blocked by a volcano. This seems like a pretty big problem; if losing the galleon is intended to be a game over, then 1) It should be made clear that you have to protect it (not really sure how you can do this though when it's your only sea unit) and 2) you should actually get a game over message when it dies. If it's not meant to be a game over, then there should be a way to get a new one.

If neither of these is a legitimate problem, then I must be missing something big; how do I get across the water?

IIRC, you can capture Fiacra, the huge bird, and use it to grab the last piece. There may be a third option (in case you've already killed it), but I cant remember, its been almost a year since I played it, then I discovered FFH and never looked back
In any case, if you search abit in the subforum, im sure you'll find what you need to do, its not a gameover.