Thanks for the suggestions, I think that'll be a good route to go.

Yeah I know about the coastlines I'm about to go over the edges to make it look a tad more hand dawn. That or I'm going to redo them completely, I'll have to see how patient I feel today.

Incidentally, the water was the easiest thing ever to do. I took one of my parchment textures, used the clone stamp, patch tool and the spot eraser to clear out the worst of the folds and crinkles, then inverted the colour. that gave me a really good base to work with and I just tweaked it a bit from there. I got the nice gradient by a combination of hand brushing with a low opacity/flow 300 soft brush for the edges, and taking a light blue land shape and guassian blurring at 250 on it's own layer..