Abstract: A spoiling apparatus for triggering a turbulent transition by autonomous disturbance and spoilers. The spoilers are mounted in multiple grooves in the circumferential direction of a navigating body, when a flow autonomously undergoes a turbulent transition, the spoilers remain in the grooves, the surface of the navigating body is free of protrusion, thus causing no additional flow resistance. A rated critical Reynolds number is set, in a case of a reduced flow speed and reduced density, the flow is a laminar flow, at which time the pressure applied to the spoilers by the flow is reduced, and the spoilers are ejected under the effect of compression springs. When ejected, the spoilers disturb the flowing of the bottom layer of the flow, and trigger the laminar flow into a turbulent flow.

Abstract: An integral hybrid electric aircraft system including a fuselage including an electrical energy source, wherein the electrical energy source includes a plurality of batteries and a fuel tank, and wherein the fuel tank contains fuel. The fuselage also including a generator in fluid communication with the fuel tank. The generator generates electricity using the fuel from the fuel tank. The system including a set of propulsors, wherein each propulsor of the set of propulsors is electrically connected to the electrical energy source and the generator and wherein the set of propulsors is configured to be powered by the generator during fixed-wing flight. The set of propulsors including at least a pusher propulsor configured to provide forward thrust and at least a lift propulsor configured to provide lift.

Abstract: Driving device for a watercraft, which device comprises a water flow channel (10) which is connected to the watercraft, preferably to the bottom thereof, and which has an inlet (11) and an outlet (12), a drive shaft (13, 14) which extends into said channel (10), a bearing shaft (15) coaxially arranged with the drive shaft part (14) in said channel, a first rotating impeller (21) connected to the drive shaft (13) for rotation in said channel (10) for the movement of water in either direction between the inlet (11) and the outlet (12), a second impeller (22) which is contra-rotating to the first impeller (21) and connected to the bearing shaft (15) for rotation in said channel (10) for the movement of water in said direction between the inlet (11) and the outlet (12), and that the drive shaft (13, 14) and the bearing shaft (15) are connected to each other via a planetary-like gearing (30), wherein one of said impellers (21, 22) is formed with an impeller casing (31) which is provided with an outer surface (322)

Abstract: A craft including a body having a front end, a rear end, two sides miming between said ends, and an axis running generally from the rear end to the front end; and a water displacement system operable to displace water to propel the craft across water and to displace water to cause the craft to rotate about said axis. The craft includes a ballast tank capable of being at least partially filled with ballast to change a position of a center of gravity of the craft to assist in rotation of the craft when capsized. The craft also includes a rapid filling and emptying system for a ballast system of a craft in addition to a water displacement system, wherein the rapid filling and emptying system includes at least one ballasting intake through which water is passed from the water displacement system into said ballast system; and at least one ballasting outlet through which the water displacement system draws water from the ballast system.

Abstract: A boat is provided with a steering arrangement comprising a main steering system and control-surface subsystem. The control-surface subsystem comprises a control-surface assembly attached to the stern of the boat and comprising a trim tab pivotally connected to the stern of the boat, and a skeg rotatably mounted by the trim tab. The control-surface assembly further comprises a trim-tab operating arrangement for pivoting the trim tab, and a skeg operating arrangement. The main steering system and the skeg operating arrangement can be selectively set to operate independently of each other, or in coordination with each other, in steering the boat.

Abstract: A vessel propulsion apparatus includes a nozzle, a deflector, and a forward bucket (hereinafter referred to as “F bucket”). In a state in which the F bucket is in a closed position and the deflector is positioned at a left side, water jetted obliquely rearward to the left from the deflector is guided by the F bucket in a left guiding direction that is tilted further to the left than a direction of jetting of water from the deflector. In a state in which the F bucket is in the closed position and the deflector is positioned at a right side, water jetted obliquely rearward to the right from the deflector is guided by the F bucket in a right guiding direction that is tilted further to the right than the direction of jetting of water from the deflector.

Abstract: Multi-directional marine propulsors for use with boats having a hull, a keel and a motor with a propeller are disclosed. The propulsor may have a cylindrical housing with fore, aft, port and starboard apertures and define a central axis when the housing is mounted to the boat. The housing may receive the propeller proximate the fore aperture such that the propeller may rotate about the central axis to provide forward thrust. An elliptical diverter gate may be mounted within the housing proximate the aft aperture for vertical rotation between port, central and starboard positions. When the gate is in port, central and starboard positions, forward thrust may exit the port, central and starboard apertures respectively. The elliptical diverter gate may be rotated between the port, central and starboard positions as desired. Alternative multi-directional marine propulsors may be mounted directly onto boat motors.

Abstract: A craft including a body having a front end, a rear end, two sides miming between said ends, and an axis running generally from the rear end to the front end; and a water displacement system operable to displace water to propel the craft across water and to displace water to cause the craft to rotate about said axis. The craft includes a ballast tank capable of being at least partially filled with ballast to change a position of a centre of gravity of the craft to assist in rotation of the craft when capsized. The craft also includes a rapid filling and emptying system for a ballast system of a craft in addition to a water displacement system, wherein the rapid filling and emptying system includes at least one ballasting intake through which water is passed from the water displacement system into said ballast system; and at least one ballasting outlet through which the water displacement system draws water from the ballast system.

Abstract: A vessel propulsion apparatus includes a nozzle, a deflector, and a forward bucket (hereinafter referred to as “F bucket”). In a state in which the F bucket is in a closed position and the deflector is positioned at a left side, water jetted obliquely rearward to the left from the deflector is guided by the F bucket in a left guiding direction that is tilted further to the left than a direction of jetting of water from the deflector. In a state in which the F bucket is in the closed position and the deflector is positioned at a right side, water jetted obliquely rearward to the right from the deflector is guided by the F bucket in a right guiding direction that is tilted further to the right than the direction of jetting of water from the deflector.

Abstract: A marine jet propulsion system has a jet pump, a venturi connected to the jet pump, and a steering nozzle rotationally mounted relative to the venturi about a first axis. The steering nozzle has a central longitudinal axis. The first axis intersects the central longitudinal axis. A first link has a first end rotationally mounted relative to the venturi about a second axis. The first link has a second end disposed generally rearwardly from the first end of the first link. A second link has a first end rotationally mounted to the first link about a third axis and a second end rotationally mounted to the steering nozzle about a fourth axis. The third axis intersects the second end of the first link. A steering arm is connected to the first link. The axes are generally parallel to each other. A watercraft having the jet propulsion system is also disclosed.

Abstract: An electronically assisted reverse gate system for a jet propulsion watercraft is provided. Control electronics are in communication with the operator interface of the watercraft to obtain commands from the operator, such as a selection between a forward, reverse or neutral mode, a braking command or a slow mode. The control electronics evaluates the target setting for these commands. This evaluation is made taking into consideration the operating conditions of the watercraft. Control signals are sent to an appropriate actuating device to adjust the gate orientation accordingly.

Abstract: A marine jet propulsion system has a jet pump, a venturi connected to the jet pump, a first steering nozzle rotationally mounted relative to the venturi about a first steering axis, and a second steering nozzle rotationally mounted relative to the first steering nozzle about a second steering axis. The second steering axis is disposed rearwardly of the first steering axis. Rotation of the first steering nozzle relative to the venturi about the first steering axis in a steering direction causes the second steering axis to rotate about the first steering axis in the steering direction and the second steering nozzle to rotate relative to the first steering nozzle about the second steering axis in the steering direction. A watercraft having the jet propulsion system and a nozzle assembly for a marine jet propulsion system are also disclosed.

Abstract: The device comprises at least one flap member (3) having a rear flap portion that runs in a plate plane, and a forward portion, as seen in the direction of motion (F). The forward portion (8) is connected to the object (2) in such manner that the flap portion (17) can be moved in the fluid transverse to the plate plane and between two positions which are on their respective sides of a neutral place (P). Furthermore, the device comprises an actuating means (8, 9) which allows a freely oscillating motion of the flap member (3; 61, 62), and a drive unit (6) for actuating the flap member (3; 61, 62) when the valve of an oscillation amplitude of the flap member (3; 61, 62) is less than a predetermined threshold value.

Abstract: An apparatus for retarding and/or changing the direction of travel of a sailing vessel is disclosed. The apparatus includes a watercraft (10) with moveable flaps (12A, 12B, 12C) internal ballast tanks, solenoid banks (20) and explosive activated nut and bolt clamps. The watercraft (10) is manually navigated or navigated by remote control. A method of utilizing the watercraft (10) to retard and/or change the direction of travel of the sailing vessel is also disclosed.

Abstract: The invention relates to a high-speed, sea-going ship comprising a double hull and a water-jet drive, the latter consisting of at least one pump assembly for generating the water-jet and at least one drive motor for the pump assembly. According to the invention, the pump assembly and its drive motor are located outside the stern area of the ship by using, in part, the space in the double hull.

Abstract: The stern hull portion of a surface ship or underwater sea craft is provided with a waterjet propulsion unit having an outlet end from which a discharge propelling waterjet emerges underwater and undergoes flow beyond the stern end of the hull between a pair of twin contoured rudders normally positioned for straight forward propulsion of the hull. The contoured rudders pivotally mounted underwater on the hull are angularly displaced by maneuvering control in opposite directions from the normal positions to maneuvering positions with their lower end tips in contact with each other to form a bucket to directionally change flow of the emerging waterjet for steering, deceleration and backing purposes during hull propulsion between low and high speeds. The twin rudders are also angularly displaced by the maneuvering control in the same angular direction for a different directionally regulated change in waterjet flow to effect turning of the hull for propulsion in a reverse direction.

Abstract: The assembly includes a nozzle adapter rotatably mounted via a pair of axles onto a jet nozzle of a personal watercraft. A hinge rotatably connects a rudder and cap onto the nozzle adapter. A torsion spring on the hinge retracts and retains the rudder and cap in a position in which the rudder extends below the nozzle and nozzle adapter thereby positioning the rudder in the water below the watercraft to provide steering capability to the watercraft. The cap covers and blocks the nozzle outlet when the engine is not operative but when the engine is operative the jet stream forces thereof acting against the cap rotate the rudder upwardly so that it extends rearwardly from the watercraft and out of its steering position. The nozzle adapter includes an inner adapter attached to the nozzle and an outer adapter attached to the inner adapter.

Abstract: The hull of a submerged sea craft adjacent its stern end is provided with auxiliary facilities for controlled maneuvering operations under low speed conditions, including steering, stopping and negative thrust backing performed independently of main propulsion of the craft. The auxiliary maneuvering control facilities include a curved channel pipe connected to two angularly related sub-channel pipe sections for selectively controlled outflow of fluid which is pressurized by a maneuvering control pump within the curved channel pipe before outflow through exit openings in the hull in different directions, as negative angle thrust jets and as steering control jets perpendicular to the hull centerline. By use of a sub-channel flow diverting flapper and gate valves at the inlet and exit outlet openings in the hull, all of the maneuvering operations may be performed under selective control.

Abstract: The invention relates to an apparatus for and method of automatically actuating the movement of a rudder of a watercraft between a steering and a non-steering position in response to the speed of the watercraft. This invention is particularly applicable for use in jet-propelled watercraft, which have reduced steering capacity at low speeds.

Abstract: The present invention relates to a steering arrangement for ships propelled by water jet, comprising a steering device (6) that is pivotal about an essentially vertical shaft (5) having a first center line (C1), at least one hydraulic cylinder (2; 3) for turning said steering device (6), which hydraulic cylinder is directly or indirectly articulately connected to the ship's body at one of its ends (2B; 3B), a turning device (4) connected to said shaft (5), for attachment to a second end (2A; 3A) of said hydraulic cylinder at a distance from said shaft (5), a reversing device (7) arranged in connection with said steering device (6) about an essentially horizontal shaft (12), an additional hydraulic cylinder (9) arranged to act on the reversing device (7), the additional hydraulic cylinder (9) following the movement of the steering device (6), characterized in that all the hydraulic cylinders (2,3,9) are arranged within a sheltered space (1) located above the extension of said vertical shaft (5), which space (1

Abstract: A watercraft includes a watercraft control mechanism that is capable of steering, decelerating, and/or trimming a watercraft without causing the stern to elevate and the bow to dive; steers or assists steering in off-power situations; steers, trims and/or decelerates a watercraft, or assists in steering, trimming, and/or decelerating a watercraft that can be stowed or retracted to minimize hydrodynamic drag at high speeds; steers, trims and/or decelerates a watercraft, or assists in steering, trimming, and/or decelerating a watercraft that does not become clogged or jammed by seaweed or flotsam or foreign objects floating in the water; and decelerates or assists in decelerating a watercraft in a smooth and stable manner when the watercraft is travelling at high speeds.

Abstract: A propulsion system designed to propel submarine and surface vessels by discharging fluid rearwardly with a reaction of increased force that is approximately twenty percent greater than that possible with conventional propeller systems. Its conical/tapered housing is mounted to the inside bottom surface and transom of a marine vessel hull whereby a keyhole-shaped inlet opening directs a large volume of seawater into the housing's wider end. Seawater then flows across several increasingly smaller propellers positioned within the housing. A reverse and steering assembly with a movable gate can be optionally aligned with the discharge end of the housing to control the direction of marine vessel movement. Size is not a limiting factor for the present invention and its operation is virtually silent. Also, its inlet opening is always below the water level so priming is never needed and no transmission is required. Recreational, commercial, and military applications are contemplated.

Abstract: Waterjet flow emerging from a jet propulsor body through a cross-sectionally circular duct is conducted through a cross-sectionally rectangular duct passage extending through transition and exhaust aft sections attached to and angularly adjusted relative thereto. Under selective maneuver controls within the propulsor body, the transition section is angularly adjusted relative to the body while pivotal vanes and flaps on the exhaust section are angularly adjusted to direct exit outflow through the exhaust section for steering and reversing purposes.

Abstract: A braking system for a personal water craft which is activated when a high velocity water jet is cut off. The braking system is comprised of a planar member attached to a rear portion of the water craft. The braking member is movable to an elevated non-operative position during a discharge of the high velocity water jet and to a lowered operative position during a cut off of the water jet. In a first embodiment of the invention, the planar braking member is automatically movable to the operative position and to the non-operative position. In a second embodiment, the planar braking member is manually elevated to the non-operative position and manually lowered to the operative position by a link or a cable.

Abstract: The invention relates to an auxiliary system for providing positive steering to marine crafts using jet propulsion systems, typically personal jet driven watercrafts such as jet boats and jet skis. In one embodiment, it includes, among other features, a combination of keel members attached to a stern section of a hull. The keels are interconnected using tie rods to the directional steering drive assembly. In other embodiments, the keels are instead attached directly to the directional nozzle or integrally made with the nozzle, and where a hood is included in the directional nozzle assembly, notches may be included in the keels to allow for full operation of the hood into its lowest position.

Abstract: The invention discloses a retractable rudder device attached to the water jet nozzle of a watercraft. In a non-deployed condition, the rudders are latched in position and completely out of the water stream underneath the craft. When deployed, two rudders aligned with the axis of the steering nozzle, are rotated into position via springs and cables. The rudders pivot independently of each other, and will retract if contact with an underwater object is made or the craft is beached. A cable system connected to a control unit lowers the rudders into the deploy position. The cable system is actuated by a hydraulic cylinder using fluid pressure from the jet pump. The deployment rate can be varied by altering the fluid pressure in the hydraulic cylinder, and is a function of boat speed. Deployment of the retractable rudder system is determined by an electronic control system.

Abstract: A watercraft is disclosed that includes a hull having port and starboard sides and a propulsion system that generates a stream of pressurized water that exits through a nozzle. A helm operatively connects to the nozzle, whereby turning the helm turns the nozzle. A vane is connected to either or both of the port or starboard sides and is operatively connected to the nozzle. The vane is capable of pivoting inwardly and outwardly in response to steering signals. The vane can also move between an operative position and an inoperative position based on pressure in the propulsion system. The vanes are designed to provide steering assistance when insufficient thrust is generated by the propulsion system to effectively steer the watercraft.

Abstract: A steering system for steering a personal water craft when a high velocity water jet which is used for propelling and steering said water craft is cut off by an engine failure. In a first embodiment, a rudder is pivotally mounted on a nozzle for rotation about a horizontal axis between an elevated non-operative position and a lowered operative position. In a first embodiment, the rudder is automatically raised to the non-operative position by an impingement of the water jet on a baffle on the rudder. When an engine failure occurs, the rudder is automatically lowered to the operative position by hydrodynamic and gravitational forces which act on the rudder. In the operative position, braking forces are generated by a fin on the rudder. In a second embodiment, the rudder is manually elevated to a non-operative position and manually lowered to an operative position by a link or a cable.

Abstract: A vessel propulsion system having a suction casing (4) configured with a suction inlet (4a) opening at a vessel bottom (1b), a suction flow path (4b) inclined to rearwardly ascend from the suction inlet (4a), and an impeller chamber (4c) formed horizontal, and disposed at a bottom of a stern, a delivery casing (10) connected to the suction casing (4) and submerged under a draft of the stern, and a set of forward and reverse rotatable axial flow blades (8) disposed in the impeller chamber (4c) of the suction casing (4).

Abstract: Presented is an improved marine vehicle propulsion system that utilizes a water accelerating rotor that operates efficiently when either partially or fully submerged all the while enclosed in a duct like a standard pump impeller pressurized nozzle waterjet. This new waterjet propulsor has a simple gas supply system without moving parts that supplies either gas or water to the water accelerating rotor dependent upon level of the waterline relative to the gas supply's inlet. One or more fluid inlet flow directing valve elements are offered that can vary the level of water reaching the rotor's inlet and can also, in an extended position, prevent water from impacting the waterjet's inlet. The latter item is valuable when the marine vehicle is either being towed or when it is being propelled by another propulsor as it reduces drag due to water flowing through an inoperative instant invention waterjet propulsor.

Abstract: The invention relates to an auxiliary system for providing positive steering to marine crafts using jet propulsion systems, typically personal jet driven watercrafts such as jet boats and jet skis. In one embodiment, it includes, among other features, a combination of keel members attached to a stern section of a hull. The keels are interconnected using tie rods to the directional steering drive assembly. In other embodiments, the keels are instead attached directly to the directional nozzle or integrally made with the nozzle, and where a hood is included in the directional nozzle assembly, notches may be included in the keels to allow for full operation of the hood into its lowest position.

Abstract: The invention relates to an auxiliary system for providing positive steering to marine crafts using jet propulsion systems, typically personal jet driven watercrafts such as jet boats and jet skis. In one embodiment, it includes, among other features, a combination of keel members attached to a stern section of a hull. The keels are interconnected using tie rods to the directional steering drive assembly. In other embodiments, the keels are instead attached directly to the directional nozzle or integrally made with the nozzle, and where a hood is included in the directional nozzle assembly, notches may be included in the keels to allow for full operation of the hood into its lowest position.

Abstract: The invention discloses a retractable rudder device attached to the water jet nozzle of a watercraft. In a non-deployed condition, the rudders are latched in position and completely out of the water stream underneath the craft. When deployed, two rudders aligned with the axis of the steering nozzle, are rotated into position via springs and cables. The rudders pivot independently of each other, and will retract if contact with an underwater object is made or the craft is beached. A cable system connected to a control unit lowers the rudders into the deploy position. The cable system is actuated by a hydraulic cylinder using fluid pressure from the jet pump. The deployment rate can be varied by altering the fluid pressure in the hydraulic cylinder, and is a function of boat speed.

Abstract: A watercraft is disclosed that includes a hull having port and starboard sides and a propulsion system that generates a stream of pressurized water through a nozzle. A helm operatively connects to the nozzle, whereby turning the helm turns the nozzle. At least one rudder connects to either or both of the port or starboard sides. The rudder is capable of pivoting inwardly and outwardly and can also be moved upwardly and downwardly with respect to the side to which it is connected. The rudder is located a certain distance from the respective side of the hull, which allows the rudder to utilize its inner and outer surfaces to assist in steering the watercraft by deflecting water flowing thereacross. Also, a linking element can connect the nozzle to the rudder. An off-power steering system is also disclosed.

Abstract: A vessel propulsion system having a suction casing (4) configured with a suction inlet (4a) opening at a vessel bottom (1b), a suction flow path (4b) inclined to rearwardly ascend from the suction inlet (4a), and an impeller chamber (4c) formed horizontal, and disposed at a bottom of a stern, a delivery casing (10) connected to the suction casing (4) and submerged under a draft of the stern, and a set of forward and reverse rotatable axial flow blades (8) disposed in the impeller chamber (4c) of the suction casing (4).

Abstract: A control mechanism for a watercraft includes a selectively movable flap connected to an actuator, which moves the flap into and out of the flow of water to affect steering, deceleration and trimming. The flap is recessed with respect to the lower surface of the hull so that it does not create drag at high speeds. The flap may be a portion of the ride plate, may be disposed in a recess in the bottom of the hull, or may be disposed on the stern above the bottom of the hull.

Abstract: A self-deploying rudder assembly for use with a water craft including an exhaust port having a exhaust stream includes a mounting assembly and a pivoting rudder blade assembly. The pivoting rudder blade assembly typically includes a thrust plate attached to one end of a rudder shaft and a rudder blade attached to the other end of the rudder shaft. When the selected thrust level is above the preselected thrust level, the thrust plate is moved out of the exhaust stream and the rudder blade is thereby moved from a deployed, operational position to a stored position.

Abstract: A jet-powered watercraft has a water jet propulsion unit driven by a powerhead and a rudder pivotably mounted to the water jet propulsion unit. The rudder is pivotable between a retracted position, where the rudder extends out of the water, and a down position, where the rudder extends in the water. Means are provided for changing the position of the rudder when the revolutions per unit time of the powerhead reaches a predetermined threshold, e.g., pivoting the rudder from the down position to the retracted position when the powerhead rpm level exceeds a predetermined threshold. In one embodiment, the revolutions per unit time of the drive shaft are detected. In another embodiment, the control position of the operator throttle control device is detected. Pivoting of the rudder may be actuated by a solenoid, a hydraulic cylinder or any other functionally equivalent electrical, mechanical or electromechanical device.

Abstract: A water craft attached to a self-deploying rudder assembly for use with an exhaust port having a exhaust stream operating at a selected thrust level includes a mounting assembly and a pivoting rudder blade assembly. The mounting assembly typically includes a mounting ring for attachment to the exhaust port, along with a storage skeg. The pivoting rudder blade assembly typically includes a thrust plate attached to one end of a rudder shaft, with a rudder blade attached to the other end of the shaft. Some deployment means, such as a spring, is used to urge the thrust plate into the exhaust stream when the selected thrust level is below a preselected thrust level. However, when the selected thrust level is above the preselected thrust level, the thrust plate is moved out of the exhaust stream and the rudder blade is thereby moved from a deployed, operational position to a stored position within the skeg.

Abstract: A rudder assembly for interfacing with a jet nozzle of a water jet propelled watercraft so as to thereby provide steering of the watercraft by pivoting of the jet nozzle even when a water jet is absent from the jet nozzle. A rudder is connected to a sleeve, wherein the sleeve is connected to the jet nozzle. In a first preferred form, the rudder extends in-line with, and immediately behind (aft of), the jet nozzle so as to be located in the water jet. In a second preferred form of the present invention, the rudder is notched adjacent the sleeve for accommodating movement of a thrust plate of a water jet propelled watercraft equipped with a thrust plate mechanism. Alternatively, the rudder may be located dependingly downward from the jet nozzle.

Abstract: A rudder assembly is attached to the nozzle of a jet-powered watercraft by a spring-loaded pivot so as to turn with the nozzle when the craft is steered. The rudder assembly has two flat plate rudders with a baffle plate attached perpendicularly between the rudders. The baffle plate partially covers the nozzle when the watercraft is at rest and is held in position by the spring-loaded pivot. At slow speeds the rudders are parallel to the water jet flow from the nozzle to aid in steering the watercraft. At higher speeds, the force of the water jet against the baffle plate overcomes the spring force to pivot the rudder assembly up and away from the nozzle such that steering is provided by directing the nozzle. In an imminent high-speed collision situation, the panic reaction is to shut off the throttle, which abruptly ends the jet flow from the nozzle.

Abstract: A retractable rudder assembly for use in steering a personal watercraft is disclosed. The rudder assembly includes at least one planar rudder operably coupled to an elongate shaft rotatably mounted on a water jet drive nozzle. The rudder is biased into a normally extended position in which the rudder extends away from the water jet drive nozzle for use in steering the watercraft at a throttle-off position. A paddle is affixed to the shaft and is positioned within a water jet flow path defined within the water jet nozzle so that the force of a water jet passed therethrough and striking the paddle at a throttle-on position urges the rudder into a retracted position with respect to the water jet drive nozzle. When the water jet drive is moved into the throttle-off position, the rudder is biased into its extended position for use in steering the watercraft.

Abstract: A watercraft is disclosed that includes a hull having port and starboard sides and a propulsion system that generates a stream of pressurized water through a nozzle. A helm operatively connects to the nozzle, whereby turning the helm turns the nozzle. At least one rudder connects to either or both of the port or starboard sides. The rudder is capable of pivoting inwardly and outwardly and can also be moved upwardly and downwardly with respect to the side to which it is connected. The rudder is located a certain distance from the respective side of the hull, which allows the rudder to utilize its inner and outer surfaces to assist in steering the watercraft by deflecting water flowing thereacross. Also, a linking element can connect the nozzle to the rudder. An off-power steering system is also disclosed.

Abstract: The inventive apparatus exercises control of the water flow which is discharged from a marine waterjet propulsor. Typical inventive embodiments comprise plural horizontal and plural vertical blade-like structures which together describe an open-ended, box-like rectilinear configuration characterized by at least two adjacent channels. Every vertical blade-like structure includes, at its aft end, a “steering” flap which is pivotable about a vertical axis. Some inventive embodiments advance marine craft reversing by implementing one or more bucket-like devices behind the inventive apparatus.

Abstract: A trim tab is provided in the internal portion of a nozzle of a jet propulsion system. The trim tab can be rotating about an axis to expose a surface of the trim tab to the jet stream of water passing through the nozzles of the jet propulsion system. The exposure of one of the trim tab surfaces creates a thrust vector in either the port or starboard direction which creates a corrective thrust, in a desired direction, which overcomes any manufacturing misalignments.

Abstract: A blow back rudder consisting of a rudder blade, rudder shaft and a plate assembly that is pivotally mounted to the nozzle of a jet nozzle of a personal water craft is spring biased in the steering mode and is positioned out of the water by the impingement force of the jet stream discharging from the nozzle acting on the plate. This provides off throttle steering. The plate is contoured to allow the plate to remain in the jet stream at low thrust and water craft speeds for rudder steering. In another embodiment, these features are contained and the plate is contoured with a concave face and its position relative to the discharge port of the jet nozzle is controlled in order to obtain reversing of the water craft.

Abstract: The instant invention describes an advanced marine propulsor that has a rotor that is, at least in its majority, enclosed by structure where the rotor receives water over at least a majority of its lower portions and gas over at least part of its upper portions. It is possible to delete the gas flow by use of one or more valves so that an approximate doubling of water flow rate occurs which is valuable as a thrust enhancer for low and mid-range marine vehicle speed operation. It is also possible to operate the rotor with water directed mainly to its lower portions but with little or no gas directed to its upper portions thus forming a partial vacuum over the upper portions of the rotor vanes. When used, a water directing valve that directs water to the rotor vanes preferably has a curvilinear water contacting surface so that water will adhere to and follow that surface. Use of port and starboard water directing valves allows varying levels of water flow to port and starboard sides of the rotor.

Abstract: Automatic swimming pool cleaning systems are disclosed. The systems include an automatic swimming pool cleaner incorporating one or more curved wipers protruding from its lower surface. The wipers and flat bottom of the cleaner induce a vortex as fluid flows to its central inlet, entraining debris in the flow. A fluted throat surrounding the inlet additionally assists the interior of the base of the cleaner in retaining debris when opened for cleaning, additionally providing an improved flow path for enhanced debris pick-up. Alternate embodiments incorporate a rudder and resistance plate for enhancing movement of the cleaners in the presence of obstacles. Also disclosed is a valve useful for controlling and indicating the rate of fluid flow to a cleaner. Included within the valve is a plunger attached to a spring, with the spring force opposing fluid flow through the valve.

Abstract: The invention provides a water jet system with higher efficiency and better steering. The water jet system uses cantilever bars for an inlet grating, to prevent blockage. The water jet system also uses an elliptical impeller shaft housing to reduce turbulence and snagging of debris by the rotating impeller shaft. The water jet system uses impeller blades with a curved cross section that curves towards the direction of forward rotation. The water jet system uses U-shaped flanges mounted to the outlet of the water jet to provide steering.

Abstract: The instant invention describes an advanced marine propulsor that has a rotor that is, at least in its majority, enclosed by structure where the rotor, in its preferred embodiment, receives water over at least a majority of its lower portions and gas over at least part of its upper portions. It is possible to delete the gas flow by use of a valve or structure so that an approximate doubling of water flow rate occurs which is valuable as a thrust enhancer for low and mid-range marine vehicle speed operation. It is also possible to operate the rotor with water directed mainly to its lower portions but with little or no gas directed to its upper portions thus forming a partial vacuum over the upper portions of the rotor vanes. When used, a water directing valve that directs water to the rotor vanes preferably has a curvilinear water contacting surface so that water will adhere to and follow that surface.