Abstract: A marine catamaran craft, comprising at least one forward hydrofoil fixed to each of the catamaran hulls and at least one rear hydrofoil in which: At least one forward hydrofoil is arranged for shallowly submerged operation At least one rear hydrofoil is arranged for shallowly submerged operation at low speeds and for planing operation at higher speeds A rear part of each of the catamaran hulls remains wetted at all speeds.

Abstract: A hydrofoil section (401) comprising upper (4014) and lower (4015, 4018, 4017) cambered profiles and a reference line in which: the reference line is drawn between the trailing edge (307) of the section and the leading edge (304) or a point close to and below such leading edge, and both profiles have a positive camber, and a substantial part of the lower profile lies above such reference line, and the area bounded by such reference line and by such lower profile lying above such reference line is greater than any area lying below such reference line.

Abstract: A marine catamaran craft, comprising at least one forward hydrofoil fixed to each of the catamaran hulls and at least one rear hydrofoil in which: At least one forward hydrofoil is arranged for shallowly submerged operation At least one rear hydrofoil is arranged for shallowly submerged operation at low speeds and for planing operation at higher speeds A rear part of each of the catamaran hulls remains wetted at all speeds

Abstract: A hydrofoil (20) for mounting to a high speed surface vessel arranged for planning operation at least at higher craft speeds and in which the trailing edge (202) remain substantially fully wetted at all craft speeds when operating under calm conditions.

Abstract: A hydrofoil section comprising upper and lower cambered profiles and a reference line in which: the reference line is drawn between the trailing edge of the section and the leading edge or a point close to and below such leading edge, and both profiles have a positive camber, and a substantial part of the lower profile lies above such reference line, and the area bounded by such reference line and by such lower profile lying above such reference line is greater than any area lying below such reference line.

Abstract: A mount for supporting part of a marine drive system to a marine hull, the mount comprising a rigid outer housing (832) defining a radially outer circumferential surface on its radially inner surface, a resilient mounting (831) disposed radially within the outer housing and defining a radially inner circumferential surface, the marine drive system passing through and supported by the resilient mounting in use, wherein a circumferential radial gap is provided either between the resilient mounting and the rigid outer housing or within the resilient mounting.

Abstract: A hub (101) for a marine propeller, the hub being formed from first (1012) and second (1011) cooperating sections which, when forming the hub, are aligned along the rotational axis of the hub, wherein the two cooperating sections define a plurality of recesses (1061) into each of which a fin assembly can be inserted, thereby forming a propeller, and wherein of the first and second sections, only the first cooperating section is arranged to be connected, in use, to a drive shaft.

Abstract: A propeller (1) comprising a hub, and a plurality of fins (3) extending radially outwards from the hub, wherein each fin is moveably connected to the hub such that, during rotation of the propeller, the dihedral of each fin can be altered and controlled over a working range by movement of that fin about one or more axes of rotation (BB).

Abstract: A propeller comprising a hub (101) and a plurality of fins (3) extending radially outwards from the hub, wherein each fin is moveably connected to the hub such that, during rotation of the propeller, either the dihedral, the rake or both the dihedral and the rake of the fin(s) can be altered and controlled over a working range by movement of the fin(s) about one or more axes of rotation; and one or more actuators for controlling the dihedral or rake of the fins independently of the pitch of the fins.

Abstract: A marine drive system mounted in the hull of a marine craft, the marine drive system comprising an engine connected to a gearbox by means of a drive shaft (532), a propeller (1) connected to the gearbox by means of a propeller shaft (501), wherein the gearbox and the propeller are formed as a single rigid body for flexibly mounting in the hull of the marine craft as a single unit, and wherein the engine, gearbox and propeller are positioned such that they are always generally aligned with the longitudinal axis of the craft.

Abstract: A fin for use on a propeller, the fin comprising a lift generating section having a leading edge and a trailing edge, and a pair of surfaces extending between the leading and the trailing edges thereby defining a tip and a root having a root chord; and a dihedral section integrally formed with the root of the lift generating section and having a rotation axis about which, in use, the lift generating system can be rotated to vary the dihedral of the fin, the axis being generally parallel to the root chord of the lift generating section.

Abstract: The application relates to water craft hulls having improved hydrodynamic stability. A hull (1) is claimed in which the center of gravity (Cg) is substantially vertically aligned with the center of hydrodynamic lift (Cp) of a lifting surface of the hull, both at lift-off speed and at design speed, and preferably also at speeds below lift-off, and at all speeds between lift-off and design speed and above. A hull having a relatively high aspect ratio at design speed, and preferably also at lift-off speed, is also claimed. In the preferred embodiment, the hull is generally delta-shaped in plan view.

Abstract: The invention relates to hulls for planing or semi-planing water craft. The hull (4) has an abruptly down-swept trailing edge portion (18) which, in the preferred embodiment, is in the form of a flap extending across the full width of the transom of the hull and which projects beyond the level of an upswept portion of the underside (14) of the hull by only a small fraction of the length (L) of the hull. According to another aspect of the invention, a hull (4) having a lightly cambered nose portion (5, 10, 12) is also described and claimed. The claimed hulls offer higher lift coefficients and lift/drag ratios than conventional planing hulls, and can operate at zero angle of attack at design speed.

Abstract: A thruster is adapted to be laterally mounted through the hull of the vessel and has propulsive ducts for opening to respective sides of the vessel and an inlet to the inboard end of both of the ducts, the inlet being at least partially provided by a tunnel having an internal cross-sectional area greater than that of the ducts, the tunnel at least partially surrounding each of the ducts and opening to each side of the vessel.

Abstract: A thruster is adapted to be laterally mounted through the hull of the vessel and has propulsive ducts for opening to respective sides of the vessel and an inlet to the inboard end of both of the ducts, the inlet being at least partially provided by a tunnel having an internal cross-sectional area greater than that of the ducts, the tunnel at least partially surrounding each of the ducts and opening to each side of the vessel.

Abstract: A propulsion system for a water craft having at least one shaft extending rearwardly form the transom of the hull of the craft and a drive system for driving the at least one shaft. A surface piercing propeller is mounted on the at least one shaft, proximal to the trailing edge of the hull, so that the propeller operates in a transom cavity created behind the hull, in use of the craft. The ratio (S/C) of the spacing of the blades to the blade cord for each propeller is at least 2.0 along substantially the whole length of the blades. The propulsion system has a high operational efficiency particularly suited for high speed marine craft.

Abstract: Suction cleaning apparatus such as a road cleaning machine comprises a closed chamber for receiving dust and similar matter together with liquid such as water intermingled therewith, the chamber having a suction duct thereto for taking up dust and similar matter from a road or like surface due to suction in the duct created by suction means such as a centrifugal fan communicating with the duct and chamber, return flow means or pipework being provided for passing water from the chamber to the suction duct for intermingling with dust or similar matter drawn into the duct. On discharge of the water laden with dust and similar matter from the duct into the chamber the laden water separates by reduction in velocity from the suction air flow while the water draining from dust and similar matter deposited in the chamber is re-circulated by the return flow means to the suction duct.