Abstract: A power boat having an improved hull including concave aft sections, and which hull is capable of operations at a wide range of speeds with low relative horsepower for vessel weight and improved fuel economy is disclosed. In one exemplary embodiment, the boat is a 38 foot power boat having an improved hull which can achieve speeds of up to about 18 knots, with a 200 hp engine and which burns about 10 gals. per hour. The hull preferably includes a negative deadrise angle at the aft sections, the deadrise angle being positive at the bow and transitioning to a negative angle at the aft sections of the hull.

Abstract: A sailboat having a novel hull shape, a fixed, shallow keel, dual rudders, and retractable, shallow dagger boards for sailing in shallow or shoal water is provided. The combination of features allows the boat to achieve performance sailing at all points of wind, and in both deep and shallow water. The hull preferably has a hydrodynamic shape which provides lift and lateral resistance to the hull when sailing. The keel is preferably shallow so that the boat may be sailed in shallow water and even beached. The draft of the keel is preferably related to the length of the hull measured along the waterline. In a preferred embodiment, there is 1 inch of draft for every 1 foot of waterline. The boat may also preferably include a set of retractable dagger boards located on opposite sides of the keel. A dagger board may be extended on the leeward side of the boat when the wind exceeds about 15 knots, in order to help prevent side slippage or leeway.

Abstract: A hydrofoil member for a sailboat of the type having a single hull with no fixed ballast includes an elongate arm portion which extends laterally outwardly away from the sailboat along a generally horizontal plane when in use. The arm portion has an upwardly-facing surface, a downwardly-facing surface, and an outer end portion which flares upwardly relative to the horizontal plane. The hydrofoil member further comprises a pontoon element mounted on the downwardly-facing surface of the arm portion at the outer end portion. The pontoon element is adapted to engage and displace water when in use for stabilizing the sailboat. The arm has is capable of being retracted to stow the hydrofoil member in a parallel position against the hull when not in use.

Abstract: An adjustable roller furling spar includes an elongated base member which is securable on a sailboat and an adjustable periphery assembly which is attached to the base member and coextends a distance therewith. The periphery assembly is adjustable to define an effective winding cross-section of the spar which is variable along the longitudinal extent thereof and which is operable for windingly receiving a sail on the spar. By properly adjusting the periphery assembly, it is operable to compensate for irregular stretch in older sails when the spar is used for reefing so that even a badly stretched sail can be maintained in a substantially flat disposition.