can you add crafting plz like add making boats
so you can go out in water and make it multyplayer

THere could be a bit more to do; the sim is a bit empty right now, but it looks and sounds great

Hmm. You could add footstep sounds for sand and water. I don't know how Unity works, but, if it is similar to UDK, it should be possible. Asides from that, I love the song and the way you applied the sea sound effect.
The textures are well tiled, except maybe for the barrels. The sand and sea look a little bit unrealistic compared to the rocks. No idea what to do about the sea, but I think a lightmap or shadowmap would help on the sand; It doesn't seem to have any shadows falling on it except for the terrain mesh shadow.
The 3d models themselves are pretty good! Imo, the pier could be a little less Rustic, and the bananas... You could add a few trees, or put things belonging to the player(camera) around them. Scattered on the ground are a little bit out of place, since no trees at all are around.
(3.5 review rating, score 3.)