A shallow water boat is shown that operates well in both shallow water and deep water. A tunnel is provided along a centerline of a flat bottom, which tunnel starts near amidships increases in depth and terminates at the aft of the shallow water boat. A top of the tunnel has an S curve therein. A front end of the tunnel connects through a series of angled holes into a plenum via a conduit to atmosphere above the maximum water line of the shallow water boat. During shallow water operation, the motor is raised and the conduit is plugged so water flows through the tunnel to the propeller for the motor. During deep water operation, the motor is lowered and the conduit unplugged so that water does not flow through the tunnel.