On many land maps you have chokepoints and other naturally defensible positions, but not so often on Water maps. My intention with this map was to provide each player with a harbor where his dock and fishing fleet would gain extra securiy from a couple of towers at the mouth of the harbor.
The script isn't perfected yet. Sometimes the "harbor" comes out as one or more inland ponds, and sometimes there is no harbor at all. I'm already working on a better version of the script, but I thought you might enjoy it as is. It seems to work better on larger maps.