Abstract: A jet boat including a hull including a keel extending in a fore and aft direction of the jet boat, at least one jet propulsion nozzle mounted to a rear of the hull, and an articulating keel attached at the rear of the hull, the articulating keel arranged to pivot about a pivot axis extending vertically or substantially vertically. A bottom surface of the articulating keel does not extend below a bottom surface of the keel when the articulating keel is parallel or substantially parallel to the fore and aft direction of the jet boat.

Abstract: A canting ballast twin foil (CBTF) sailing yacht constructed according to the invention includes a sailing hull, a ballast, a ballast-supporting structure, and an onboard ballast drive system. The ballast drive system moves the ballast in order to vary the counter-heeling force it produces underway. Twin foils that depend downwardly from the hull in positions fore and aft of the ballast provide leeway and steering control. An onboard main engine drive system provides power, either directly by suitable mechanical coupling or indirectly through charging of the battery/electric system, for one or more of a canting system, a leeway, and/or steering control system. The onboard main engine drive system may also power a yacht-propelling propeller.

Abstract: An asymmetric wing for decreasing the leeward drift of a vessel has two different surfaces, one of which is cambered in cross-section and the other which has less camber in cross-section or flat. The asymmetric wing has a leading edge pointed toward the bow of the vessel and the trailing edge pointed toward the stern of the vessel. The surfaces of the asymmetric wing can be selectively moved to the port or starboard sides of the vessel. For centerboard and sliding keel vessels, a pair of asymmetric wings are installed in trunks, each asymmetric wing having a first cambered surface and a second less cambered surface. The first cambered surfaces of the two asymmetric wings point in opposite directions. At any one time both asymmetric wings are not moved into the water. The asymmetric wing is applicable to vessels without a centerboard or sliding keel trunk. In such a case, a horizontal shaft extends through a single asymmetric wing and the single cambered surface is rotated to either port or starboard.

Abstract: A boat hull including a center depending keel fin is provided and the keel fin includes an upstanding rear edge portion having a horizontally rearwardly opening transverse recess formed therein. An upstanding main fin extending generally longitudinally of the hull is oscillatably supported in the forward portion of the keel fin recess for angular displacement about an upstanding axis spaced forward of the horizontal longitudinal center of the main fin and an upstanding front-to-rear extending servo fin is oscillatably supported from the rear portion of the main fin for angular displacement relative thereto about an upstanding axis. The interior of the hull includes heel sensing drive structure operatively connected between the hull and the servo fin for displacing the latter to starboard relative to the main fin in response to starboard heeling of the hull and displacing the servo fin to port relative to the main fin in response to heeling of the hull to port.