Click the map name to see an image.
Bering looks like it might fit (
http://forum.shrapnelgames.com/showthread.php?t=39550), though I'm not sure if it has ports to allow the land nations to go from land mass to land mass.
Galadia is really nice but a bit larger than desired (
http://forum.shrapnelgames.com/showthread.php?t=43594)