Abstract: A water jet propelled craft equipped at the rear section of the craft with a water jet pump driven by an engine. A cylindrical member is provided so as to extend backwards around the rear end of a pump outlet nozzle of the water jet pump, and an outlet of exhaust gas from the engine opens backwards between the outer surface of the pump nozzle and the inner surface of the cylindrical member.

Abstract: A small-sized marine craft has a floor allowing a navigator to ride thereon, the floor being provided in an aft or rear portion of a deck constituting the upper portion of the craft body. Upwardly projecting fins are respectively formed on both sides of the floor. Further, a forward-slanting wall member is provided on a portion of the deck forwardly of each of the fins. An operating member used to control the engine of the craft is installed on the forward-slanting wall member.

Abstract: The marine jet propulsion unit of this invention, in preferred form, has a pair of laterally adjacent blade carriers, each having a vertical outer surface movable in a horizontal orbit and to which blades are fixed that project edgewise outwardly. Each blade has a surface facing in the direction of its orbital movement that is concavely curved along its height. The two blade carriers, at opposite sides of a fore-and-aft extending vertical plane of symmetry, are driven in opposite orbital directions such that each has a driving portion remote from the plane of symmetry that moves rearward in an acceleration channel and has an opposite forwardly moving portion adjacent to the plane wherein its blades are interleaved with those of the other. Water entering a forward intake is guided in two streams, one to the front end of each acceleration channel, and the rear end of each acceleration channel is communicated with a discharging outlet nozzle.

Abstract: A jet actuated boat propulsion device is provided for driving a boat in areas where hyacinths or other water vegetation exists, and which normally would foul up the operation of an outboard or inboard motor. A water pump positioned in a well in the bottom of the boat and communicating with the water in which the boat is floating is connected through conduits to discharge a jet of water through a nozzle extending into the body of water in which the boat is floating. The jettisoned water being discharged into the body of water exerts a jet action or thrust which drives the boat through the water.

Abstract: A water jet propulsion system for watercraft having an impeller, especially a conical oblique flow impeller with an increased outer diameter in going toward the downstream side. The impeller is secured to a transmission shaft which is journalled by bearings in a hub of fixed blades and formed at its end portion with spline grooves being able to fit in spline strips formed at the forward end portion of a drive shaft. This allows a pump portion of the water jet propulsion system to be assembled outside the watercraft and separately therefrom, so that positioning of the impeller with respect to its duct can be effected with a high degree of accuracy.

Abstract: A steering apparatus for an outboard jet engine utilizes a channel or conduit along the underside of a boat hull in combination with a channel or conduit extension member to guide water to the inlet port of the jet outboard propulsion apparatus, the bottom lip of the inlet port being disposed proximate the extended bottom surface of the underside of the boat hull with the top lip or rim of the inlet port being disposed proximate the extended top surface of the channel of conduit along the hull to permit propulsion and steering of the boat while the boat hull is planing along the surface of water only inches or centimeters above the bed of the lake, river or ocean.

Abstract: The invention relates to a steering mechanism for a water-jet propelled craft having a rotatable propulsion nozzle. The mechanism comprises a fine steering control and a coarse reversal control. The controls rotate the nozzle via a differential gearbox consisting of four meshed bevel gears rotatable in bearings within a gear cage. The steering control is operative to rotate a gearbox input shaft via a worm and pinion reduction gear, and the reversal control is operative to rotate the cage. The nozzle is connected to a gearbox output shaft. The reduction gear inhibits torque feedback from the reversal control to the steering control and torque feedback from the steering control to the reversal control is inhibited by hydraulic ram actuation of the reversal control.

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 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 reversible hydrojet boat drive for the substantially nonturbulent nozzling of water during the forward mode, and effective non jamming seal function during the reverse mode, and comprised of an exact nozzle continuation of the exit passage of the pump, particularly the top wall thereof, and the compatible eccentric relation of the surrounding seals of the reverse gate centered below the axis of gate rotation, thereby to avoid jamming and to eleviate strain on the control system therefor.

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 water jet propulsion system for use with boats having an impeller duct which discharges a stream of liquid through a nozzle to propel the vessel in a forward direction. A reversal plate is provided which occludes the rearward jet opening and causes the stream to exit through a pair of reverse movement ports, one disposed on each side of the nozzle to direct the water jet from the impeller duct forwardly and preferably also slanted downwardly when the boat is to be reversed.

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: A low draft, hydroplane-like vehicle in which the engine and associated equipment is so located in the hull that the engine not only drives a jet pump to power the vehicle but the weight .Iadd.and location .Iaddend.of the engine and associated equipment.[.imparts an.]..Iadd., relative to the center of buoyancy of the vehicle, renders the vehicle stable only when it is in an upright position, and the vehicle will immediately right itself from any overturned position. In addition, the weight and location of the engine and associated equipment imparts an .Iaddend.imbalance to the vehicle except when a user is mounted thereon. Due to this imbalance .[.the vehicle is stable only when in an upright position, and will immediately right itself from any overturned position. A further result of this imbalance is that.].