This is a fantastic map.
I have just a few tweaks I saw. The coastline and title are darker than any other features. If the coast line I think would look better if it was a closer match to the fade into the ocean.
The texture might work better as an overlay. Right now if you look close you can see everything is sitting on top of it.
The ship is great but I would scale it down a bit. This is just my artistic whim.
Some of the ocean shading I would tweak especially near the Farrain Islands. Some of the spots are not islands. I would either take them out or create lighter shading through the whole area. This would make the shading more noting shallow seas. You could even throw in a tiny sinking ship as a hazard marker on the map. Again my artistic whim.

Even though I nit pick the details I want to repeat that I think this is a truely fantastic map.

I loved the plaster pattern, I can see using it as an overlay to create a crinkle pattern on paper.