“The present invention is predicated on the realization that the combined functions normally assigned to the keel of a sailing yacht can be better effected without a conventional keel. Instead, a laterally swingable ballast is provided and carried on a strut, the portion of which is adjustable to provide the desired counter-heeling force, but which need provide no particular leeway control. Fore and aft underwater sailing foils of high efficiency and adjustable camber provide greatly enhanced steering and directional control, and, further enable the yacht so provided to sail with controllable and adjustable leeway, which may indeed be zero.

More particularly, the present invention provides a keelless hull in which the hydrodynamic side force function (leeway control) and gravitational ballast function (angle of heel control) required for upwind sailing are provided by new and separated appendages. A heavy streamlined ballast appendage is mounted at good depth separate from and under the mid-body of the hull by means of a narrow strut swingable to port or starboard from a bearing in the hull to adjust the lateral position of the ballast and the amount of counter-heeling force. Fore and aft foils provide leeway, rolling and steering control, and roll damping functions which are structurally and hydrodynamically separated from the ballast appendage.”

CBTF is a patent protected technology. A simple license agreement based on the length of the boat will be required of the boat owner. The license fees are separate from design fees and are a charge for the latest performance technology.

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CBTF Co., Inc.
+1 (619) 232-8664


©2005 CTBF Co.