[mandrill7]

I've been playing around with something similar for the reefs around Midway Atoll. (Hence all my recent questions about textures! :wink: )
I took a screenshot of shallow water and created a texture tile from it, then saved it as a LAND texture file. Drew on the reefs in map_c, blurred them and filled with the reef tile on map_t. I've just about cracked it; I now have a band of 'water' denoting the reefs, that's almost indistinguishable from the surrounding shallows, with waves breaking on it. Ships won't cross it (boo, I wanted them to be wrecked when they struck it!)

I was thinking of using this idea for swamps too; creating a 'watery swamp' land tile and placing it in a shallow lake. Similar to your idea.

Can you keep me informed of how things work out? I'm still working on the map_c and it will take me a while to get onto tiles, etc.