A couple things I thought about last night about your map, you might want to split it up into part, as it is right now, its a very big open map with lots of water, 2 things that are going to cause HUGH fps hits on their own, mixed together its gonna be a VERY laggy map (It'll also be an hour plus compile time for the map). You should make them going into caves with one or two entrances each to the next area, or just have have ALOT of fog on the map.