Well done for getting to where your at. Are you printing it off or interactive image?

Think at the min your try to hit it with a sledge hammer, it's lacking finesse. I think your grid doesn't help, try a bigger scale grid every 1000miles with legend for smaller units. I feel that your labelling wrong. Every Feels like the same importance. Little islands maybe italic bended round the island.

Your right about the saturation seem very heavy. You embossing off all the islands doesn't help, it doesn't convey any information such as heights or places, dock. How about some current lines or wind lines.

Think you have a way to go, but your making good steps.