It seems like it is missing the two arm/wing things. Your style reminds me of Yu-Gi-Oh cards :3
Those wings are the sails of the ship.
The thing is if i show more of them the head has to remain too small/too cluttered around in the middle of the picture, considering its demanded that icon be showing it from the side opted to do it like this.
I would fade the sky and water from light to dark going towards the horizon, but that's just me.
now thats something i can give a try at, brb.
Also wanted to say something:
If you have took a look at the actual model its an long ass ship, its length is already being too compressed just to fit into the icon. So if somebody happent to have an fantasy about fitting the whole ship in without it appearing heavily bloated: Sorry, not going to happen.