Hey I also looked at the map finally, though only in the editor. About boats, well, we alked about these before, so you know my opinion

. Some other notes:
-During the first year of wc3, there was a map called "Treasure island" which was played in some pro tournaments. It sill still available on epicwar:
Treasure Island - Warcraft 3 Maps - Epic War.com So the name might not be ideal.
-Unfortunately, my world editor crashes everytime I try to open the object manager for this map.
-Gold coins, I'm not sure why dont see them in other melee maps. When some thing like that is the case, there is often a good reasons; however I dont know any. They fit well into the map/lore of course.
-The sea giants on the islands are not on camp stance, is that intentional?
-I think there are not enough trees near the main bases. Wood income will be slowed down due to increased walking distances, except for nightelves.
-Speaking of which, none of the creepspots look attractive for AoE creeping to me.
-Some of the brown creep camps could drops in tomes.
-THe gold mine creep in the middle will attack trespassing units, but I guess thats hard to avoid given the general layout. Some creeps at the shipyards to the same.
-It is possible to walk around some forests on the outside. There is some minor asymmetry in this respect.
In general, I think you achieved what you intended, and (for a boat map) it is a good map.
edit: Ok that last comment might sound mean. Wasnt intentional. Sorry.