Thanks @Ryan-Yates that is helpful. Unfortunately I'm not entirely sure how I'd use that in the physics calculations. What I envision for figuring out the lift generated by the hydroplane tunnel/air trap would be to setup a grid of points at an angle. I can then sample the water at the center of each square to find the height above the water. From there I'm not sure what the equation is to figure out the lift force exerted by the air pressure. I'm thinking it may be similar to ground effects.