A new wave of thought

I figured the shaft rotation was opposite to compensate each other and make the ship run a straight line better, but this squat thing is new. I can see that with a speedboat you raise the bow with acceleration until it planes out and is riding more on top of the water. I suppose since a ship isn't going to plane out on top of the water, it could end up plowing more of it if it wasn't running flat with the stern up and only a little lower than the bow. Or does it have to be dead flat? A better milage trick?