GB2117712A - Buoyant craft with hydrovane - Google Patents

Abstract

The craft comprises a hull which may be a hydrofoil and which is of sufficient positive buoyancy to support the payload of the craft, the hull being provided with hydrovanes 6 preferably positioned at the rear of the hull and which are capable of overcoming the positive buoyancy of the hull when the craft is propelled through the water. The craft preferably comprises a rudder 7 disposed near the front of the hull and the centreline thereof. <IMAGE>

Description

SPECIFICATION Water-borne craft The invention relates to water-borne craft and more particularly, but not exclusively, to small water-borne craft for leisure or sporting purposes. It is known to provide a water-borne vessel comprising a floating hull which when the vessel is driven at speed is supported above the water surface on hydrofoils. It is also known to provide submarine vessels which are driven below the surface of the water by suitably adjusting the buoyancy of the vessel and/or by means of hydrovanes on the vessel which act in conjunction with the vessel's propulsion means.

According to the invention I provide a water-borne craft comprising a hydrofoil of sufficient positive buoyancy to support the payload of the craft, the hydrofoil being provided with at least one hydrovane capable of overcoming the positive buoyancy of the hydrofoil when the craft is propelled through the water. Thus when the craft is driven at speed the hydrovane(s) can be operated to submerge the hydrofoil, e.g. to render the craft less susceptible to wave influences.

Preferably the craft comprises a pair of hydrovanes mounted at the rear of the hydrofoil, disposed on opposite sides of the centreline of the hydrofoil and which can be used independently not only to affect the buoyancy of the craft but also its trim and its steering (pitch, roll and yaw). Preferably the craft also comprises a rudder disposed towards the front of the hydrofoil and on the centre line thereof.

The hydrofoil may be shaped to resemble an arrow head in plan view and in cross-section preferably resembles a symmetrical aerofoil section. It might however be desirable to modify the "lift" characteristics of the hydrofoil by altering its cross-section e.g. to provide a degree of negative lift. The hydrofoil may be provided with a ballast tank or tanks to adjust its buoyancy and/or its trim and if desired means could be provided for varying the ballast load during use of the vessel. Where the hydrofoil is constructed of a plastics or other suitable resilient material it might be possible to construct the hydrofoil as a hollow closed vessel and vary the inherent buoyancy of the hydrofoil by adjusting the air pressure within the closed vessel so as to alter its volume.

The hydrofoil is preferably formed on opposite sides with a pair of upwardly inclined stabilizing fins. These fins are preferably disposed towards the rear of the hydrofoil and preferably form smooth extensions to the hydrofoil when the craft is viewed in plan. If desired one or more additional hydrovanes may be provided on the hydrofoil, e.g. at the front or at the side thereof.

In an example of a one-man craft in accordance with the invention, the operator is carried on a platform above the hydrofoil and operates the rudder with his feet and the hydrovanes with his hands. In this particular example the propulsion means is an outboard engine mounted on the hydrofoil behind the operator. The outboard engine may be mounted with the propeller driving shaft extending through an aperture in the hydrofoil so that its propeller is disposed below the hydrofoil while the engine is carried at a height which is above the water level when the hydrofoil is submerged. It will be appreciated that the operator and/or passengers could be carried in a cockpit which is formed in, or at least partly in, the hydrofoil. The invention is diagrammatically illustrated by way of example in the accompanying drawings.

1. A water-borne craft comprising a hull of sufficient positive buoyancy to support the payload of the craft, the hull being provided with at least one hydrovane capable of overcoming the positive buoyancy of the hull when the craft is propelled through the water.

2. A water-borne craft according to claim 1, wherein the hull is formed as a hydrofoil.

3. A water-borne craft according to claim 1 or claim 2, comprising a pair of hydrovanes mounted at the rear of the hull.

4. A water-borne craft according to claim 3, wherein the pair of hydrovanes are disposed one on each side of the centreline of the hull and wherein the hydrovanes can be used independently of one another.

5. A water-borne craft according to any preceding claim comprising a rudder disposed towards the front of the hull and on the centre line thereof.

6. A water-borne craft according to any preceding claim, wherein the hull is a hydrofoil shaped to resemble an arrow head in plan view.

7. A water-borne craft according to claim 6, wherein the hydrofoil resembles in crosssection a symmetrical aerofoil section.

8. A water-borne craft according to any preceding claim, wherein the hull is provided with at least one ballast tank to adjust its buoyancy and/or its trim.

9. A water-borne craft according to any preceding claim, wherein the hull is a hydrofoil formed on opposite sides with a pair of upwardly inclined stabilizing fins.

10. A water-borne craft according to claim 9, wherein the stabilizing fins are disposed towards the rear of the hydrofoil.

11. A water-borne craft according to claim 10, wherein the stabilizing fins from smooth extensions to the hydrofoil when the craft is viewed in plan.

1 2. A water-borne craft according to any preceding claim, wherein the operator is carried on a platform above the hull and compris

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (14)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Water-borne craft The invention relates to water-borne craft and more particularly, but not exclusively, to small water-borne craft for leisure or sporting purposes. It is known to provide a water-borne vessel comprising a floating hull which when the vessel is driven at speed is supported above the water surface on hydrofoils. It is also known to provide submarine vessels which are driven below the surface of the water by suitably adjusting the buoyancy of the vessel and/or by means of hydrovanes on the vessel which act in conjunction with the vessel's propulsion means. According to the invention I provide a water-borne craft comprising a hydrofoil of sufficient positive buoyancy to support the payload of the craft, the hydrofoil being provided with at least one hydrovane capable of overcoming the positive buoyancy of the hydrofoil when the craft is propelled through the water. Thus when the craft is driven at speed the hydrovane(s) can be operated to submerge the hydrofoil, e.g. to render the craft less susceptible to wave influences. Preferably the craft comprises a pair of hydrovanes mounted at the rear of the hydrofoil, disposed on opposite sides of the centreline of the hydrofoil and which can be used independently not only to affect the buoyancy of the craft but also its trim and its steering (pitch, roll and yaw). Preferably the craft also comprises a rudder disposed towards the front of the hydrofoil and on the centre line thereof. The hydrofoil may be shaped to resemble an arrow head in plan view and in cross-section preferably resembles a symmetrical aerofoil section. It might however be desirable to modify the "lift" characteristics of the hydrofoil by altering its cross-section e.g. to provide a degree of negative lift. The hydrofoil may be provided with a ballast tank or tanks to adjust its buoyancy and/or its trim and if desired means could be provided for varying the ballast load during use of the vessel. Where the hydrofoil is constructed of a plastics or other suitable resilient material it might be possible to construct the hydrofoil as a hollow closed vessel and vary the inherent buoyancy of the hydrofoil by adjusting the air pressure within the closed vessel so as to alter its volume. The hydrofoil is preferably formed on opposite sides with a pair of upwardly inclined stabilizing fins. These fins are preferably disposed towards the rear of the hydrofoil and preferably form smooth extensions to the hydrofoil when the craft is viewed in plan. If desired one or more additional hydrovanes may be provided on the hydrofoil, e.g. at the front or at the side thereof. In an example of a one-man craft in accordance with the invention, the operator is carried on a platform above the hydrofoil and operates the rudder with his feet and the hydrovanes with his hands. In this particular example the propulsion means is an outboard engine mounted on the hydrofoil behind the operator. The outboard engine may be mounted with the propeller driving shaft extending through an aperture in the hydrofoil so that its propeller is disposed below the hydrofoil while the engine is carried at a height which is above the water level when the hydrofoil is submerged. It will be appreciated that the operator and/or passengers could be carried in a cockpit which is formed in, or at least partly in, the hydrofoil. The invention is diagrammatically illustrated by way of example in the accompanying drawings. CLAIMS

1. A water-borne craft comprising a hull of sufficient positive buoyancy to support the payload of the craft, the hull being provided with at least one hydrovane capable of overcoming the positive buoyancy of the hull when the craft is propelled through the water.

2. A water-borne craft according to claim 1, wherein the hull is formed as a hydrofoil.

3. A water-borne craft according to claim 1 or claim 2, comprising a pair of hydrovanes mounted at the rear of the hull.

4. A water-borne craft according to claim 3, wherein the pair of hydrovanes are disposed one on each side of the centreline of the hull and wherein the hydrovanes can be used independently of one another.

5. A water-borne craft according to any preceding claim comprising a rudder disposed towards the front of the hull and on the centre line thereof.

6. A water-borne craft according to any preceding claim, wherein the hull is a hydrofoil shaped to resemble an arrow head in plan view.

7. A water-borne craft according to claim 6, wherein the hydrofoil resembles in crosssection a symmetrical aerofoil section.

8. A water-borne craft according to any preceding claim, wherein the hull is provided with at least one ballast tank to adjust its buoyancy and/or its trim.

9. A water-borne craft according to any preceding claim, wherein the hull is a hydrofoil formed on opposite sides with a pair of upwardly inclined stabilizing fins.

10. A water-borne craft according to claim 9, wherein the stabilizing fins are disposed towards the rear of the hydrofoil.

11. A water-borne craft according to claim 10, wherein the stabilizing fins from smooth extensions to the hydrofoil when the craft is viewed in plan.

1 2. A water-borne craft according to any preceding claim, wherein the operator is carried on a platform above the hull and compris ing foot actuated means for controlling a rudder and hand actuated means for controlling the hydrovanes.

1 3. A water-borne craft according to any preceding claim, comprising means for mountng an outboard engine with the propeller driving shaft thereof extending through an aperture in the hull so that its propeller is disposed below the hull while the engine is carried at a height which is above the water level when the hull is submerged.

14. A water-borne craft substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.