Abstract: A boat hull having a tunnel structure along the bottom of the hull in the form of a truncated hollow partial cone indentation and extension parallel to the keel of the boat. The tunnel has a cone shape and has a truncated end attached to the bottom of the hull near the keel and a constant radius extension to an open end attached to the transom of the boat. The tunnel encloses a propeller shaft extending from the boat interior at the truncated end is cone shaped to the position of a propeller partially within the tunnel and then has a constant radius extension to the transom of the hull. The tunnel extension directs the forces from the propeller to the stern of the boat and the increased area surface of the bottom in a manner that increase the lift on the stern to assist in getting the boat into planing attitude from a starting attitude.

Abstract: A boat hull having a tunnel structure along the bottom of the hull in the form of a truncated hollow partial cone indentation parallel to the keel of the boat. The tunnel has a truncated end attached to the bottom of the hull near the keel and an open end attached to the transom of the boat. The tunnel encloses a propeller shaft extending from the boat interior at the truncated end, the propeller shaft, a propeller and a rudder. The angle of the cone with respect to the keel places the propeller about 45% to 50% within the tunnel at planing attitude or speed. The combination of the tunnel placement along the hull and the axis of the propeller shaft increases the efficiency of the boat and reduces fuel consumption.