Tip: Layer 3 backgrounds and tides disappear when you hit a message box, so unless you apply this fix, plan your level around that. For example, you can add a sublevel without layer 3 at the start/midpoint, and include your message there.
Forgive my rudeness, but it really doesn't look like an airship. There is nothing to indicate this thing can fly and for Miyamoto's sake it has cobwebs on it! What kind of vehicle - let alone a flying one - has cobwebs on it? It really needs a better tileset.
Very well, I'll take your word for it. Some suggestions though: First, remove the BG scrolling. All of it. Stars are much too far away to look anything short of ridiculous when moving around in the BG. Slap some clouds on BG3 and have those scroll instead. Add some propellers/jets or something to give it look of an airship rather than a flying bundle of sticks (maybe you have this already, what do I know). Please note that I'm not trying to being you down, I just want the level to be as good as possible.
Hmm, doesn't look like the fire from their lightning will turn out that great as they're currently placed. That can be easily fixed, but what's the justification for the fire not being killed by the wind?
This is the first room out of 3. It's kinda finished, however, I'm not sure which background to use. I also don't know if the tileset's okay or not, as the logships were replaced in Nin's level as well. I also am considering to make this an indoor area instead of another Ship level, as that'd make sense when you play Nin's part, as Morton goes into the pipe.