Abstract: A stern screw has a tunnel tube inside which a propeller is rotatable about a shaft. The propeller is driven by a drive motor at least during operation. The stern screw is placed entirely below water level. For this purpose, the tunnel tube has an opening for accommodating therein an intermediate part which is profiled at a first side, forming part of the wall of the tunnel tube, and at an opposite side is provided with a flange for fastening to an outside of a stern of the boat. The intermediate part has a cavity in which a drive shaft is accommodated by which the propeller is driven. The drive motor is mounted in its entirety on the inside of the stern.

Abstract: Disclosed is a device used to maneuver a vehicle consisting of a tubular y with suction circumferential slots adjacent its forward end and exhaust circumferential slots adjacent its aft end on both the outer and inner peripheral surfaces. Fluid is conveyed between the forward slots on one surface of the tubular body to the aft slots on the other surface of the body to produce asymmetrical pressure on the tubular body while traveling through a fluid medium.

Abstract: An improved thrust director unit is provided for discharging a directionally adjustable water jet flow from the hull of a marine vessel to generate a thrust reaction force for close-quarter maneuvering and/or propulsion of the vessel. The unit comprises a thruster housing having an outlet through which the jet flow is discharged, wherein the outlet is defined by diverging fore and aft walls to permit angularly forward or rearward jet flow discharge for vessel propulsion. At least two deflector vanes are movable together within the housing outlet and cooperate therewith to define a directionally adjustable discharge flow path for selective jet flow discharge in a sideward direction to produce a sideward thrust, or in a forwardly or rearwardly angled direction to respectively produce a reverse or forward propulsion thrust. In the sideward thrust position, the discharge flow path has a nondiverging cross section and is isolated from the diverging fore-aft walls of the housing outlet.

Abstract: A vessel having a hull of effective rectangular configuration and utilizing a dual propulsion and steering arrangement, including sails and an eight jet system, thus making the vessel extremely maneuverable.

Abstract: An auxiliary thruster for a marine vessel. The auxiliary thruster includes a submersible propulsion unit which has a shroud with a propeller rotatably mounted therein. A canned electric motor is mounted between the propeller and the shroud for rotating the propeller to create thrust. A propulsion unit deploying and rotating mechanism is mounted on the hull and on the propulsion unit. The propulsion unit deploying and rotating mechanism is operable to extend the propulsion unit out of the hull and retract it into the hull and to rotate the propulsion unit to direct the thrust generated thereby in any desired direction when the thruster is in the deployed position. When the thruster is retracted, it is positioned with a tunnel extending transversely through the hull. Rotation of the propeller while in the retracted position generates laterally directed thrust through the tunnel.

Abstract: A hydrojet for ships, intended for use in shallow waters, has a semiaxially bladed impeller with a vertical axis of rotation rotatably arranged in a well-shaped housing. The drive for the impeller is introduced into the housing from the top through a cover plate, and the housing is closed at the bottom by a bottom plate which has a water inlet arranged in the center for axial admission to the impeller and at least one flatly sloped water outlet. A control device in which the water delivered by the impeller is fed to at least one outlet nozzle without conversion of kinetic energy into pressure energy, is arranged between the discharge end of the delivery channels of the impeller and at least one water outlet. The control device forms a ring channel without blading. The water inlet is designed asymmetrically.

Abstract: A thrust propulsion mechanism (10) for a boat (12) includes an outlet conduit (22) extending athwartships from a first outlet port (16) to a second outlet port (16') in the hull (18). A paddle-wheel impeller (24) is mounted within the hull for rotation about an axis of rotation (34) by a reversible motor (30). A circumferential paddle (58) portion of the paddle-wheel impeller extends into an aperture (26) defined centrally in the top wall of the outlet conduit. An inlet conduit (20) extends athwartships from a first inlet port (14) to a second inlet port (14'), and intermediate thereof supplies water to the center of the paddle-wheel impeller. Water is discharged from the paddle-wheel impeller through one of the outlet ports, dependent on the direction of rotation of the paddle-wheel impeller, to create thrust by a combined paddle-wheel and centrifugal pump action.

Abstract: An amphibious vehicle has a watertight vehicle body and at least two elongate buoyancy tanks, with a mechanism for displacing the buoyancy tanks between operative positions, in which the buoyancy tanks extend parallel to opposite sides of the vehicle body, and inoperative positions, in which the buoyancy tanks extend parallel to one another along the top of the roof of the vehicle body. A pair of propulsion units can be lowered from the vehicle body for supporting the vehicle during travel into a body of water and for propelling the vehicle through the water. Each propulsion unit comprises an elongate body, propellers in a duct extending longitudinally through the body and side openings from the duct to permit steering by rotation of the propellers.

Abstract: An improved thruster system is provided for maneuvering and/or propulsion of a marine vessel, through the use of directionally oriented water jets discharged tangentially from a helical-conical flow chamber. The thruster system includes a high capacity pump for pumping water through a hull intake to the flow chamber with a substantial helical or swirling action. The water exits the flow chamber through one or more of a plurality of tangentially oriented discharge conduits having discharge nozzles for passage of high velocity water jets through the hull, resulting in reaction forces used to maneuver or propel the vessel. Each discharge conduit includes a valve member movable between open and closed positions for respectively permitting or preventing water flow to the associated nozzle.

Abstract: A steerable bow thruster (12) system is located substantially within the pontoons (20) of a semisubmerged vessel (10) exclusive of a rotating nozzle (42) which is located on the upper side of the pontoons. The rotating nozzle can turn in any direction and allows the steerable bow thruster system to thrust forward, aft and side to side and in any direction in between to allow the semisubmerged vessel to maneuver freely and without the assistance of the main engines. To minimize draft and to prevent ecological harm, the nozzles are installed on top of the pontoons allowing the pontoons to act as a barrier to keep thrust wash from disturbing shallow ocean bottoms and reefs over which the vessel may be operating. The propelling means may be shrouded to prevent harm or injury to swimmers who may be in the water. A rudder (44) may also be coupled to the thruster nozzle to provide directional control for the semisubmerged vessel when it is underway at higher speeds.

Abstract: The nozzle ring associated with the propeller and rotatable together with it around the vertical axis is designed as a partially open annulus and arranged such that the inner circle of the nozzle--and consequently practically the wing tip circle as well--approximately touches the respective local separating surface between the flow and the floating body or boat.

Abstract: A retractable and storable thruster for a vessel, using a trapezoidal deformably rotatable device producing rectilinear movement inside a well in the vessel's hull. A casing (1) is sealingly fixed on joint planes in a well (2) which is an integral part of the structure (3) of the vessel. Within this casing (1) are folded two arms (4) and (5) pivoting asymmetrically, a motor (10), a stirrup (17) secured to the motor, and a propulsion screw assembly. The two arms (4) and (5), on the one hand, are pivoted at (6) and (7) on the casing (1) and, on the other hand, at (8) and (9) on the stirrup (17) secured to the motor (10). Under manual or mechanical action (X) or (Y) exerted on a lever (12) secured to the arm (4) by a shaft (6), this arm (4) in compound rotation with the triangulation arm (5) causes the deformation of the trapezium obtaining a rectilinear movement in a direction parallel to axis (A Z) of the motor (10) at its axis (11).

Abstract: A water-jet propulsion system for ships, which are intended to be used in shallow waters. A semi-axial, bladed turbine wheel with a vertical axis of rotation is disposed so that it can rotate in a well-shaped pressure housing. Into the pressure housing, the driving mechanism for the turbine wheel is introduced from above through a cover plate. At the lower end, the pressure housing is closed off by a bottom plate, which has a concentric, centrally disposed water inlet for axial flow against the turbine wheel and at least one water outlet with a shallow inclination. A guiding apparatus in which the flow energy of the water conveyed by the turbine wheel is largely converted into pressure energy is disposed between the outlet end of the conveying channels of the turbine wheel and the at least one water outlet.

Abstract: A V bottom hull watercraft powered by a pair of jet propulsion units that are supported for pivotal movement about horizontally disposed pivot axes and rotary movement about a longitudinal pivot axis to rotate the water inlet openings and elevate them from a downwardly facing normal operating position and an upwardly facing service position. The water inlet openings are disposed so that they extend parallel to the sides of the V bottom. Steering nozzles are supported for pivotal movement at the discharge ends of the jet propulsion units and pivot about vertically extending axes that are not perpendicular to the water inlet openings so that no vertical thrust will be exerted on the watercraft hull when the steering nozzles are pivoted to effect steering.

Abstract: A vessel propulsion system, the vessel having longitudinally spaced forward and rearward zones comprising a motor-driven pump having a suction inlet and a discharge outlet; two laterally spaced, forwardly directed jet openings to the vessel forward zone, and two laterally spaced, rearwardly directed jet openings at the rearward zone; structure including multiple valves in fluid path communicating between the jet openings and the pump suction inlet, and between the jet openings and the pump discharge outlet; and also between the forward and rearward jet openings, and; control structure to selectively control the valves to cause water jetting in directions to alternatively:propel the vessel forwardlypropel the vessel rearwardlybrake vessel movementturn the vessel to the rightturn the vessel to the left.

Abstract: Paired spaced electrically driven motors provide a steerable propelling system for small boats. Each motor drives a propeller carried in an elongate channel, communicating from each lateral side of a boat beneath the water line to one boat end, to move water through such channels for boat propulsion. The electrical motors are of variable speed, reversible, and separately controlled by a joystick type control device to provide differential control of motor speed to allow steerage. The propelling system provides a low speed, maneuverable propulsion system for fishing use, as an auxiliary power system for boats having a separate principal powering system, and to aid maneuverability alone or in conjunction with the principal powering system.

Abstract: A ductless wall thruster for a marine vessel has a housing with a plenum chamber therein and, at a forward end of the housing, at least one inlet opening surrounding an outlet opening. An impeller is rotatably mounted within the housing so that when the impeller is rotated, it draws water into the housing and discharges it through the outlet opening to create a thrust. Preferably, there is a plurality of equally dimensioned inlet openings defined by stationary vanes inclined in a direction opposite the normal direction of rotation of the impeller. The outlet opening is preferably defined on a forward end of a central impeller housing in which the impeller is mounted, with the impeller having a flow area therethrough which is greater than the flow are through the outlet opening.

Abstract: A method and apparatus for trimming a boat to adjust the angle of attack of the boat relative to the water, which comprises passing the boat through the water at a speed sufficient to cause an intake conduit located on the after portion of the hull, and preferably at the stern of the boat to receive water. The received water is passed from the stern via a transfer conduit to the bow of the boat. The received water is then expelled downwardly out of the bow via a discharge nozzle at a velocity sufficient to create a reaction force great enough to create a bow-lifting moment upon the boat hull. In addition, the trim system can control the velocity of flow of the water expelled from the discharge nozzle to thereby control the reaction force and the bow-lifting moment.

Abstract: The device comprises a thruster assembly which consists of a housing, thruster motor, thruster propeller, and thruster motor control device. When integrated into a stern mounted main drive, the thruster housing becomes integral with the main drive. The thruster is situated on the transom just above the bottom line of the hull with its axis in line with the transom, horizontal with the water line, and at right angles to the main drive. The thruster control device is connected to the boat's steering wheel linkage so that when the wheel is turned the thruster is activated. Turning the steering wheel causes the thruster to push the boat's stern at right angles to the main drive thus causing the boat to turn. The direction the wheel is turned determines the direction of thrust (right or left) and therefore, the direction the boat turns. Additionally, thruster control can be achieved by connecting the thruster control device to the throttle/shift lever.

Abstract: A propeller thruster installation includes a propeller unit rigidly supported in an inner tunnel tube which in its turn is elastically coaxially supported in an outer tunnel tube which is rigidly secured to the hull of a ship. In order to reduce the transmission of noise and vibrations from the propeller unit to the interior of the ship an annulus between the outer and inner tunnel tubes is filled with, a continuously maintained "bubble curtain" of air.

Abstract: A jet propulsion system is provided for ships. Port and starboard ductways are provided with radial constrictor axial-flow impellers, and the output flow therefrom is divided between hull-bottom and hull-side discharge outlets. A stabilizer system is provided comprising pivotal deflectors in the hull-side jet outlets and means to automatically control these deflectors responsive to both rate of roll and angle of roll to counteract rolling of the vessel.

Abstract: A drive mechanism particularly for flat-bottomed watercrafts with at least one centrifugal pump or the like producing a water jet, which pump is arranged closely above the intake opening within the watercraft and within an elbow which is pivotal for controlling the watercraft and the blades or the like of which pump are connected by a ring or the like.

Abstract: A small boat bow thruster which includes a port and starboard discharge nozzle forwardly mounted through the hull of the boat above the water line. Water from an inlet port located below the water line of the boat is drawn by a pump through conduits to the discharge nozzles. The pump is a bi-directional positive displacement pump which can feed either the starboard or port discharge nozzle depending on the direction of pump rotor rotation. The pump is powered by an electric motor capable of running in a normal or reversed mode and which is controlled by an activation switch manually operated. Water is discharged through the port or starboard nozzle above the water line of the boat when the system is activated. The bow is thrust sidewise in the direction opposite of the nozzle discharge allowing slow and controlled maneuvering of the boat in tight spaces.

Abstract: A cable-supported tree cutting device for use with drag lines and the like provides a tool body having a pair of opposed jaws positioned at one end of the tool body and movable with respect to one another so that the jaws can open and close. An open-ended mouth portion is adapted to receive a tree therebetween to grip or cut same. A counterweight portion of the elongated body generally opposite and spaced from the open mouth is provided and a lifting eye is positioned between the jaws and the counterweight for forming a connection with a flexible cable.

Abstract: An automatic rudder attachment for outboard jet motors. A rudder attachment is designed to provide steering capability at low or drifting speeds when the jet thrust is reduced and during reverse direction when the jet thrust is reversed. The rudder swings up to a retracted position when the jet motor is operating and provides sufficient thrust for steering. The rudder is pivotally attached over the jet nozzle whereby the water race effects the vertical swing of the rudder.

Abstract: A steering and propulsion system for a ship, including two side by side, fore and aft pipes underneath a ship's hull, and compressed air or steam delivered through tubes around an exterior of the hull to the two pipes, and controls to eject forwardly or rearwardly out from the pipes.

Abstract: This invention is a hydraulic auxiliary power system for a sailboat, and includes a sea-water-driven turbine pulling water from ahead of the hull and forcing it behind the rear of the hull; the turbine being powered by solar energy.

Abstract: When the right turn or left turn is set by operating one joystick lever, the bow thrustor arranged on the bow side generates the drift thrust in the rightward or leftward direction in accordance with the turning angular velocity on the basis of the operation of the joystick lever. At the same time, the propellers provided on the stern side are controlled so as to generate the backward thrust proportional to the absolute value of the turning angular velocity of the ship. The forward thrust of the ship which is caused due to the generation of the drift thrust by the bow thrustor is suppressed. Thus, the ship is turned to the right or left around the stern as a rotational center at a predetermined speed with the position of the hull held.

Abstract: A pivotal bow thruster adapted to be adjustably pivoted about a stem of a boat, which enhances attainment of smooth, safe docking of the boat, with better control, and minimal difficulty. The bow thruster comprises two propellers which, when spinning, thrust the bow of the boat to starboard or to port, and a mechanism for pivoting the propellers about the stem of the boat. This pivoting mechanism comprises a pivoting arm coupled to the propeller unit and a gear train which, when activated, rotates the pivoting arm.

Abstract: A wall thruster for surface or submarine vessels that is cavitation resistant and does not require a hull duct. The invention comprises an impeller mounted in a swirl chamber such that seawater is rotated under pressure. The water is then discharged through streamlined nozzles in a direction to minimize mixing with the flow of the water being drawn into the impeller.

Abstract: A propeller thruster installation includes a propeller unit rigidly supported in an inner tunnel tube which in its turn is elastically coaxially supported in an outer tunnel tube which is rigidly secured to the hull of a ship. In order to reduce the transmission of noise and vibrations from the propeller unit to the interior of, an ship the annulus between the outer and inner tunnel tubes is filled with elastic gas cushions, or a continuously maintained "bubble curtain" of air.

Abstract: The location of azimuth thruster propellers at the parallel hulls of semisubmersible offshore vessels, is arranged so the water jet from a propeller at one hull, which is occasionally directed towards the adjacent hull will pass mainly below last-mentioned hull. When thruster propellers are arranged in pairs the bottoms of the hulls will preferably be inclined upwardly/outwardly within the portion around a thruster propeller located outside of a longitudinal middle plane through the hull. In order to facilitate the docking of the vessel, the bottom plating in the fore and aft bodies of the hulls, where the thruster propellers are mounted, should be raised sufficient to prevent the propellers projecting below the base lines of the hulls.

Abstract: A Marine Jet Propulsion System for use as an inboard engine for boats is herein described. An engine or motor means is attached in a driving relationship to a pump and thrust output apparatus. Heat generated by and rejected by the engine or motor is passed into the pump base for dissipation into the outputted jet thrust stream. Air and/or exhaust gas from the engine is ejected around the jet output stream to reduce against-the-hull turbulence and jet stream or thrust energy losses. Streamlining hull closures for the jet pump intake and output ports are provided to reduce system hull drag when not in use and to limit marine organism growth inside the pump.

Abstract: This disclosure relates to a side thruster for a ship. The thruster includes a propeller mounted in a cylindrical tunnel formed on the ship, and a housing-support is connected between the propeller and the hull of the ship for supporting the propeller in the tunnel. The housing-support extends substantially transversely of the direction of water flow through the tunnel, and it is generally elliptical in cross section. At least one enlargement is formed on the outer surface of the housing-support for reducing the effect of K/a/ rm/a/ n vortexes, and the enlargement preferably spirals around the outer surface of the housing-support.

Abstract: An improved boat thruster system including a pump for drawing water through an inlet in the boat hull and for discharging water through first and second pipes connected to outlets located on either side of the hull. A valve is installed in each of the pipes to control the flow of water therethrough. The valves may be controlled by either an open or closed loop control system configured so as to prevent both outlet pipes from being closed at the same time during system operation. Each valve is preferably comprised of multiple vanes each of which is mounted for rotation about an off center axis such that in the event of a valve control system failure, the water flow will cause the valve to open rather than close thereby preventing undesirable high pressure buildup in the system.

Abstract: A spherical vehicle for operation in a fluid medium utilizes an actuator disk or propeller of approximately half the diameter of the sphere for propulsion. In addition to providing the energy for driving the sphere, the actuator disk acts to draw the flow of fluid smoothly over the after part of the sphere, thus avoiding or minimizing the tendency of the flow to separate from the surface of the sphere and create turbulence. For aircraft launch, a heavy shroud protects the actuator disk propeller and assures that the vehicle will sink rapidly after impact. The shroud is jettisoned at a desired depth. Steering in pitch and yaw planes is effected through the use of a plurality of powered thrusters located at or just behind the circle of maximum diameter (with respect to the direction of motion) and selectively actuated by a guidance or control system. Alternatively a single reversible thruster may be used for steering in yaw combined with a movable internal weight for pitch control.

Abstract: An improved boat thruster system including a pump for drawing water through an inlet in the boat hull and for discharging water through outlets on both sides of the hull. The improved system includes a plurality of substantially planar vanes mounted in the water flow path proximate to said outlets. The vanes function to reduce swirl angle components in the water flow and thus increase thrust efficiency and to prevent the ingestion of water borne debris into the outlets.

Abstract: A water-jet drive mechanism for driving and controlling a watercraft includes a substantially cylindrical support housing which is supported for rotational movement about a substantially vertical pivot axis in a cylindrical recess in the undersurface of the watercraft, with its undersurface flush with that of the watercraft. A centrifugal water pump is encased in the support housing so that its inlet and its discharge nozzle open through the undersurface of the support housing. The pump drive shaft is inclined and lies in a vertical plane arranged at an angle to the direction of water discharge from the nozzle. A normally open ventilating valve provided in a wall of the pump is closed by the flow of water through the pump.

Abstract: A drive mechanism for ships or the like having at least one main propeller or the like drivable by at least one main motor and further having at least one drivable auxiliary mechanism, for example a maneuvering propeller. An energy producer is drivable by the main motor. A further motor is driven by the energy producer and arranged for driving the drivable auxiliary mechanism. An adjusting mechanism is provided for adjusting energy emitted by the energy producer or absorbed by the further motor. A regulator adjusts the adjusting mechanism to a preselected energy output. The main motor and the auxiliary mechanism are sized such that in the higher part of the speed range of the main motor, the sum of the energy required to drive the propulsion means at that speed and simultaneously drive the auxiliary mechanism at that speed exceed the output available from the main motor.

Abstract: A water-jet drive mechanism for driving of watercraft and including an elbow located in the hull of the watercraft and containing a pump or the like by which water is sucked in at the bottom of the watercraft through a suction passage and is ejected downwardly through an ejector passage. A gas is supplied to the water jet at the ejector passage.

Abstract: A lateral thrust rudder for a ship includes a cross-channel extending transversely through the ship from one side thereof to the other side and a water conveying mechanism such as a propeller is provided in the cross-channel. A guide vane is pivotally mounted on a horizontal axle at each end of the cross-channel and extends inwardly into the cross-channel. The lower part of each end of the channel is rounded so it flares outwardly. Normally the guide vanes are controlled solely by water flow through the cross-channel but, where necessary, a drive mechanism can be provided for the vanes.

Abstract: The invention relates to an air-cushion vehicle comprising a hull, two air propulsion units located at a considerable distance from each other and one or several drive engines for the propulsion units. One of the propulsion units is located at the front end of the vehicle at one side of its longitudinal axis. The other unit is located at the rear end of the vehicle at the opposite side of said axis.

Abstract: A steering system comprising a propeller in a flow duct across a ship is provided with a wedge shaped valve to shift the flow direction between the sides of the ship, which wedge shaped valve has its vertical pivot shaft in the wedge center line directed into the onflow and its wedge sides arranged as flow guides.

Abstract: The device comprises a main support housing which is secured to the hull of a vessel. An opening is made within the lower portion of the housing through the vessel hull to allow a thruster drive assembly to lower into operative position. The drive assembly includes an upper gear housing which mounts a drive gear. The upper gear housing is pivotally mounted for rotation about the axis of rotation of the drive gear. The opposite end of the upper gear housing is pivotally attached to a vertically displaceable lower gear housing which mounts an idler gear and a propeller. The idler gear drives a ring gear disposed about the propeller. When the upper gear housing is moved about its pivot axis, the lower gear housing moves vertically causing the propeller to move from a recessed position to an operative position below the bow of the boat to provide lateral thrust to the boat.

Abstract: Disclosed is a detachable jet propulsion unit adapted to be externally mounted on the hull of a water craft. The propulsion unit comprises (a) a base, a first side of which is shaped to conform closely to the exterior of the hull of a water craft and which contains a plenum for water maintained at high pressure, (b) an apparatus for introducing water at a high pressure into the plenum in the base, (c) a plurality of jet nozzles carried by the base and in fluid communication with the plenum in the base, and (d) a mounting assembly for detachably mounting the base on the exterior hull of a water craft. A plurality of the propulsion units may be mounted on the hull of the water craft for propelling the water craft by cyclically expelling water through the nozzles sequentially from the bow to the stern of the water craft.

Abstract: A hydro-jet drive for watercraft. A device is provided applicable for mounting in the hull of a boat by which a jet stream can be created and directed in any desired direction for movement of the boat accordingly. There is provided an elbow having an intake portion and a substantially horizontal discharge opening. The elbow is rotatable on an axis of rotation and contains a suitable motor driven impeller. A motor driven device is provided for rotating the elbow about the axis of rotation thereof for effecting discharge in an operator determined direction. The axis of rotation of the impeller is arranged eccentrically with respect to the axis of rotation of the elbow. The device is particularly adaptable for shallow draft vessels.

Abstract: A hydraulic pump driven by any suitable power source, such as by an electric motor energized from a storage battery supplies water under hydraulic pressure by way of a control valve unit to a plurality of pairs of downwardly and outwardly-inclined nozzles disposed at various locations around the boat's hull above the water line thereof. These include a forwardly-located pair of nozzles on the starboard and port sides respectively and also three pairs of nozzles near the stern of the boat, the first pair upon the starboard and port sides being directed downward and forward for backward maneuvering, the second pair being directed downward and outward on the starboard and port sides respectively for side-wise maneuvering, and the third pair being directed downward and rearward also on the starboard and port sides for forward maneuvering. A first modification makes use of a downwardly and rearwardly directed nozzle with an optional flow-reversing deflector amidships on the transom of the boat.

Abstract: The invention pertains to reversing apparatus for hydraulic jet marine drives utilizing a pivoted steering nozzle and a reversing gate adapted to divert a jet of water into a reversing nozzle. The reversing nozzle is rotatably mounted upon the steering nozzle and utilizes orientation apparatus fixed with respect to the axis of the steering nozzle such that rotation of the steering nozzle in one direction produces rotation of the reversing nozzle about its axis in the opposite direction. The relative movements of the steering and reversing nozzles produces force vectors in the nozzles in a common lateral direction with respect to boat movement wherein a high degree of boat control while being reversed is achieved at low pumping capacity.

Abstract: An improved boat thruster including a diverter valve having an inlet connected to a water pump and a pair of outlets extending to either side of the boat. Each outlet includes a primary nozzle and a deflector movable to a first position wherein it allows water flow from the primary nozzle to be discharged to one side to thus thrust the boat to the opposite side. Each deflector is also movable to second and third positions for directing the primary nozzle water flow to respective secondary nozzles for discharging the water either forwardly or rearwardly to thus thrust the boat in the opposite direction. The secondary nozzles each have an exit area smaller than that of the primary nozzle.

Abstract: A sea thermal power plant is provided with pumps of the propeller type for bringing up cold water and forcing it through suitable condensers or heat exchangers and for drawing a continuous flow of warm water from a surface layer of the sea and forcing it down through suitable heat exchangers or boilers of the plant. The water so drawn from the sea flows through the heat exchangers and is subsequently discharged therefrom, which action creates thrust thereby producing forces to move the plant over the water surface. The heat exchangers are provided with deflectors which control the direction of discharge to produce a reaction force in any desired direction to drive the power plant. The pumps have associated therewith pipes which have located therein, downstream of the pumps, bypass louvres or vanes which can be opened to discharge water directly into the sea to produce a higher thrust for moving or positioning the power plant.