I think toning down the color of the land might work as well. It seems to weigh down the left hand side of the map. I think you might need to model the text somewhat as well. The crispness of the text seems to conflict with the overall weathered appearance, that is just my opinion though.

I like the idea of a map on dark media, especially one where the water is brighter than the land. That is the map style of a sea born scourge. Where the sea exists, their prey exists as well, land is unknown and foreboding. If this is to be a navigational map for water based predators, I would push the western continent even further to the margins to emphasize the water area (and most tasty shipping routes. Also, you may want to add currents in white much like rivers on a land map. Pirates would want that information readily available.

I really like this map, I feel it is very well done. I also feel that if you push it a bit further, you can have something really special and extremely unique.

I suggest you push it further by treating the water as the important information. maybe you delineate the political boundaries of the sea. Where do the Fyhmal Corsairs hold sway, where would you find Theilipian Privateers? Is there a swift current that takes you from the north to the southeast? Often times in maps water is taken for granted, but a map for a pirate game... oh, that could be a different story.