This is cool.  How do you propose to remove bump underneath?  Post work? Bump on ship and its reflectivity to match wet look of ground would be good.  Or perhaps dupulicate ship, use a glass material with your bump applied and the duplicate raised one bryce unit.  If you post the bump out underneath, maybe use a smoothing brush or the like around the edges between rain and no rain to add to realizm.  

I can suggest it but I can't do it.  Good work