Abstract: A resilient trim plate which, when mounted in cantilever fashion on the bottom of a boat and when adjusted, provides for trimming of the boat when the boat is underway and moves over the water. The trim plate is provided with fasteners for rigidly securing the forward portion of the trim plate to the bottom of the boat at a location forwardly of the transom or aft end of the boat. The trim plate extends rearwardly from the attachment means in cantilever fashion and presents a curved or convex lower surface to the water. The curvature of the lower surface of the trim plate can be increased or decreased to thereby increase or decrease the pressure difference between the upper and lower surfaces of the trim plate when the boat is moving over the water. Such pressure difference generates a downward force on the trim palte and thereby the boat much in the same manner the creation of a lift force as air flows over the wing of an airplane in flight.