Unit Model

Here's a strange situation: I have a unit which is have to make underwater. So, I made it fly at a negative height, which works. However, the animation effects around the unit (waves and stuff that the boat makes) stay, and you see the basic outline and the waves the unit is making, underwater.

What I want to know is if I can do any of these (or if not, please suggest ways I can do it):
-Make the unit have no model file at all. I tried, but in-game it didnt appear on the minimap, wasnt selctable, and made no waves. Is there an alternate way to do this?
-Disable the animations that appear around the unit (the waves).

Those are the only ways I can think of. Giving it permanent invisibility didnt work either, the waves still appears and it made the unit overpowered.

I think waves are built into boat models, but i could be wrong.

Yeah, they're emitters, and emitters usually do not listen to the size/negative height of the model they're attached to. :(

But is there a way I could change the model to be nothing, but still be selectable? Becuase right now it looks like crap.