Abstract: A sailboat keel structure, wherein the keel has an elongated body with fore and aft edges, and a generally elliptical cross-section. An elongated slotted opening is formed along the aft edge between the upper and lower ends of the keel, with the opening extending forwardly to a point generally aft of the minor axis of the elliptically configured keel so as to create an internal chamber in the keel with an aftward opening. A plurality of bores are formed in the keel and extend diagonally from forward ports along the outer surface of the keel to aftward ports along the inner lateral surfaces of the internal chamber. While the bores may be generally cylindrical in their configuration, they are preferably tapered from a smaller diameter at the forward port to an increased diameter at the aftward port.