The concept for the variable tunnel, which has a patent pending, is a simple solution to several flaws inherent in the classic tunnel hull. Most tunnel hull boats run poorly in deep water because of their reduced bottom surface, which in turn decreases the displacement - this normally increases a boat's draft at rest. The VT system solves both these problems by incorporating a tunnel pad that raises and lowers within the tunnel in conjunction with the jack plate. As you raise the engine to run shallow, the pad rises and the cavity increases to accommodate skinny water. When you lower the jack plate, the pad covers the tunnel to provide a smoother ride. The pad is made from a specially designed carbon fiber and closed-density hard-core foam material that also increases the boat's flotation and displacement so that it can still be poled in less than 6 inches of water.