Abstract: A mechanical joint for transferring rotational motion between shafts at an angle and related assemblies. The assemblies can include both fixed and adjustable-angle joint housings for providing high torques in hard to reach areas. Other assemblies include improvements in inboard marine drives that correct the prop angle to generally align with the direction of travel of the boat and outboard marine drives with improved drive trains.

Abstract: An inflatable motor boat with a U-shaped hull in plan view and configured to operate in shallow water. An inflatable bottom is attached to the hull and comprises an inclined longitudinal tunnel having an arc-shaped form in cross section. A portion of the tunnel is wedge-shaped with an angle of inclination from 5° to 45°. The width of the tunnel can be reduced in a rearward direction, and an upper surface of the tunnel can have a sinusoidal shape in a longitudinal section.

Abstract: An aquatic vessel may include contra-rotating propellers and a hull mold with a keel pad sectional extended from a hull planing surface to a location on the hull mold at which a propeller shaft exits a propeller shaft tunnel at an aft transom edge of the hull mold and at a forward portion of the keel pad sectional, with sides of the propeller shaft tunnel formed into directional ports to increase a flow of water into the propeller shaft tunnel.

Abstract: A hull mold of an aquatic vessel may include a keel pad sectional extended from a hull planing surface to a location on the hull mold at which a propeller shaft exits a propeller shaft tunnel at an aft transom edge of the hull mold and/or at a forward portion of the keel pad sectional, with sides of the propeller shaft tunnel formed into directional ports to increase a flow of water into the propeller shaft tunnel.

Abstract: A boat comprising a propeller tunnel formed in a hull. The tunnel has a forward end and a rearward end. The rearward end defines a shaped upper surface transverse to a longitudinal axis of the propeller tunnel. An output shaft extends from the propeller tunnel. A propeller is provided that rotates on the output shaft and comprises a plurality of blades defining: outer diameter and radius dimensions, a forward plane perpendicular to the output shaft and defined by a forward-most extension of said blades, and an aft plane perpendicular to the output shaft and defined by an aft-most extension of the blades. A protrusion is provided terminating aft of the propeller and inwardly extending from the propeller tunnel. The protrusion defines a curved portion that terminates in a tip portion, wherein a longitudinal distance between the tip portion and the aft plane is less than the outer diameter dimension.

Abstract: There is provided an item which floats in a body of water. The item includes a body having a surface provided to form at least part of the underside of the item and an opposing surface. The item includes apparatus comprising at least one channel which passes between the surfaces and allows the passage of water therethrough. A means provided to influence and/or be influenced by the passage of the water through the at least one channel to exert a propelling and/or controlling force on the item.

Abstract: A ship has a water flow forming path (3) formed in a bottom (2), and a propeller (6) disposed in the path (3) and a rudder (8) on a rear side of the propeller (6). A movable side of the rudder (8) faces toward a bow (1a). As a result of this, thrust increases due to generation of a rapid stream by the propeller (6) in the path (3), the propulsion performance improves and the steering performance improves because the rapid stream in the path (3) acts on the rudder (8). An outboard motor (14) may be provided with a vertical channel (13) in a stern (4) of the boat. Replacement can be made through the vertical channel (13). As the propeller (6) of the outboard motor (14) is recessed, it is possible to pull the boat onto the beach while leaving the outboard motor (14) as it is.

Abstract: A stern structure of a ship includes a plurality of propellers, a plurality of propeller shafts and a stern structural body. A plurality of propeller shaft tubes is provided correspondingly to the plurality of propellers, and the plurality of propeller shafts connected to the plurality of propellers is inserted into the plurality of propeller shaft tubes. The stern structural body extends backwardly from the stern body, spreads externally with respect to a ship body center line C, and contains portions of the plurality of propeller shafts extending backwardly from the stern body. An inner side of the stern structural body is equivalent to an interior portion of a ship body. The stern structural body supports the plurality of propeller shaft tubes in the interior portion of the ship body.

Abstract: A boat including a propeller tunnel portion formed in a hull of the boat in which a propeller rotates on an output shaft that extends from the propeller tunnel. A protrusion having a curved portion terminates in a tip portion. The protrusion extends from the propeller tunnel portion and the tip portion terminates near the aft plane of the propeller. The placement of the protrusion in the propeller tunnel portion can be shown to improve propulsion efficiency.

Abstract: There is provided a boat (200) including a hull (20), and two engines (30, 50) couplable to rotationally drive mutually spaced separate corresponding propeller assemblies for providing thrusts. Directions of the thrusts are angularly adjustable (?1, ?2) relative to the hull (20). A control unit (70) receives first and second user commands (S1, S2) and sends corresponding signals for controlling powers (P1, P2) coupled from the engines (30, 50) to their propeller assemblies. The control unit (70) determines a difference in power (?P) to be coupled to the propeller assemblies as a function of the first and second user commands (S1, S2). The control unit (70) controls coupling of power (P1, P2) to the propeller assemblies so that the propeller assemblies develop a difference in thrust which is a function of the difference in power (?P).

Abstract: A boat hull includes a pair of spaced apart cavities formed in the bottom thereof. Mounted within each cavity is an electric trolling motor. An air purge system is provided for purging air from each cavity when the boat rests on a water surface. Additionally each cavity is closed at front and rear ends and is open from the bottom. The depth of each cavity varies from front to rear with a maximum depth occurring generally intermediately between the ends. In operation each trolling motor generates a propulsion stream of water that is directed generally rearedly and downwardly from the rear end of each cavity.

Abstract: A shallow water boat is shown that operates well in both shallow water and deep water. A tunnel is provided along a centerline of a flat bottom, which tunnel starts near amidships increases in depth and terminates at the aft of the shallow water boat. A top of the tunnel has an S curve therein. A front end of the tunnel connects through a series of angled holes into a plenum via a conduit to atmosphere above the maximum water line of the shallow water boat. During shallow water operation, the motor is raised and the conduit is plugged so water flows through the tunnel to the propeller for the motor. During deep water operation, the motor is lowered and the conduit unplugged so that water does not flow through the tunnel.

Abstract: An improved tunnel configuration for tunnel mounted surface piercing propellers. The improved tunnel configuration provides a flooding suction to the tunnel to allow flooded propeller operation at speeds below planning. The tunnel is stepped whereby an upper portion of the tunnel is sized to allow the propeller to draw air at high speeds. The lower portion of the tunnel is sized to allow the propeller to be flooded resulting in smooth acceleration, improved handling in forward and reverse and a reduction of the transition period.

Abstract: A shallow draft boat has a hull that protects a propulsion propeller within a tunnel that passes only partially through the hull from stem to bow. The hull causes mixing of water and air at high pressure during motion of the boat through the water, creating lift and a pressure gradient that keeps the tunnel filled. The boat prevents propulsion unit malfunction by keeping obstacles, such as debris, crab pots and mammals such as manatees from contact with the propeller.

Abstract: An improved tunnel configuration for tunnel mounted surface piercing propellers. The improved tunnel configuration provides a flooding suction to the tunnel to allow flooded propeller operation at speeds below planning. The tunnel is stepped whereby an upper portion of the tunnel is sized to allow the propeller to draw air at high speeds. The lower portion of the tunnel is sized to allow the propeller to be flooded resulting in smooth acceleration, improved handling in forward and reverse and a reduction of the transition period.

Abstract: A marine vessel and drive combination includes port and starboard tunnels formed in a marine vessel hull raising port and starboard steerable marine propulsion devices to protective positions relative to the keel.

Abstract: A watercraft hull having a pair of laterally spaced propulsion tunnels located on opposite sides of its keel, with said tunnels being open downwardly towards the water, includes a movably mounted keel section located between said propulsion tunnels to prevent water crossflow between said tunnels and increase dynamic lift on the hull.

Abstract: A recreational boat comprising a boat hull having a bottom and a top deck. Formed in the bottom are two spaced apart elongated cavities that extend substantially the entire length of the boat. Disposed in each cavity intermediately between the front and rear of the boat is an electric trolling motor. Each electric trolling motor is independently controlled by a foot pedal mounted on the top deck. Hence, the boat is propelled by the trolling motor and can be steered by independently controlling each of the electric trolling motors.

Abstract: A marine vessel and drive combination includes port and starboard tunnels formed in a marine vessel hull raising port and starboard steerable marine propulsion devices to protective positions relative to the keel.

Abstract: A shallow draft boat has a hull that protects a propulsion propeller within a tunnel that passes only partially through the hull from stern to bow. The hull has a mechanism, such as a flap for selectively permitting or blocking water flow access to the tunnel from under the boat. The boat also has a lift mechanism preferably in the shape or adjustable parallelogram for selectively positioning a propeller of a propulsion unit substantially directly behind the tunnel or below the tunnel. The boat can operate in two modes. In one, water access to the tunnel is permitted and the propeller is positioned above the bottom of the hull and behind the tunnel. In the other, water access to the tunnel is blocked and the propeller is positioned below the bottom of the hull. This construction permits selective operation in a shallow draft mode, in a normal draft mode or in between.

Abstract: The current invention is an apparatus and method for an inner and outer dual hull boat capable of transforming between different levels of planing ability. The design is a gateway in the outer hull which allows water to pass through the void between the inner and outer hull. By controlling the position of a gate, the flow of water through the gateway in the forward moving boat can be controlled, which allows for the control of the planing or displacement capacity of the boat.

Abstract: A seagoing boat is driven by at least two rudder propellers and has a hull for transporting cargo or passengers. The rudder propellers are preferably embodied as electric rudder propellers. The hull has an approximately rectangular cross section amidships, to which flow-directing bodies are connected. A flow channel is configured between the skegs, the flow channel being embodied in a wedge-shaped manner with a continuous, preferably slightly bent enlargement in the direction of the bottom astern. The side walls of the flow channel are configured at least in part as even surfaces and taper off in the form of fin-shaped teeth having water displacement volume. The streaming effect of the flow channel generates a low boat resistance. The influence of the flow channel on the wake has a positive effect on the propulsion efficiency.

Abstract: A nozzle drive propulsion assembly for use with a marine craft and incorporating an annularly configured nozzle disposed in surrounding relation to a propeller collectively mounted exteriorly of the marine craft and preferably, at least partially, within an elongate recessed channel formed in the hull. A strut assembly is connected to the nozzle in transverse relation to a trailing open end thereof, downstream of the propeller and in at least partially supporting relation to the propeller. The nozzle includes a collection assembly including a water collecting chamber incorporating a pitot-type structure for directing water into the collecting chamber and along a path of fluid flow in the strut assembly to a thrust member mounted on the strut assembly. A rudder assembly and a deflector structure are secured to an exterior of the nozzle and function to determine the craft's direction of travel.

Abstract: Vessel provided with a propeller protruding beyond the hull fitted in a propeller tunnel that extends as far as the stern of the vehicle. The surface area of the propeller tunnel recessed in the hull in a direction perpendicular to the longitudinal axis of the vessel is essentially constant over the length of the cavity. The width of the cavity increases in the upstream direction to the end of the tunnel.

Abstract: A water sports performance boat includes a hull having a sharpened angle keel for cutting into the water. Reverse chines are carried on port and starboard sides and extending from a forward portion of the hull to an aft portion for inducing a lifting of the bow at generally low boat speeds and for providing a stabilizing effect. Port and starboard spray pockets are located at the aft portion of the hull for reducing a side spray of water near the transom. Performance strakes are formed within the hull with each extending from an aft position rearwardly to the transom. An elliptical shaped dispersion tunnel formed along the keel within an aft most portion of the hull extends through the transom and provides a desirable wake shape.

Abstract: A boat hull having a tunnel structure along the bottom of the hull in the form of a truncated hollow partial cone indentation and extension parallel to the keel of the boat. The tunnel has a cone shape and has a truncated end attached to the bottom of the hull near the keel and a constant radius extension to an open end attached to the transom of the boat. The tunnel encloses a propeller shaft extending from the boat interior at the truncated end is cone shaped to the position of a propeller partially within the tunnel and then has a constant radius extension to the transom of the hull. The tunnel extension directs the forces from the propeller to the stern of the boat and the increased area surface of the bottom in a manner that increase the lift on the stern to assist in getting the boat into planing attitude from a starting attitude.

Abstract: A boat propulsion system includes a boat having an elongated hull with a water flow channel formed in the bottom thereof, wherein a movable trim plate is disposed within the water flow channel for controlling a flow of water to a surface-piercing propeller which is positioned aft of the water flow channel and which is disposed within a propeller cavity formed in the bottom of the hull. In a fully extended position, the trim plate is flush with the hull of the boat, and in a fully recessed position the trim plate is completely recessed within the water flow channel. The trim plate is variably movable between the recessed and fully extended positions to provide for performance advantages at various boat speeds.

Abstract: Vessel provided with a propeller protruding beyond the hull fitted in a propeller tunnel that extends as far as the stern of the vehicle. The surface area of the propeller tunnel recessed in the hull in a direction perpendicular to the longitudinal axis of the vessel is essentially constant over the length of the cavity. The width of the cavity increases in the upstream direction to the end of the tunnel.

Abstract: An inboard propeller drive system for shallow water boats comprising a stern tunnel and a propeller drive shaft sub-assembly. The tunnel protrudes upwardly from the floor of the boat, and has an S-shaped bottom plate immersed in water. The sub-assembly includes a housed drive shaft, a propeller, a cavitation plate, and a steering mechanism. The forward end of the sub-assembly is pivotally mounted on opposing inner walls of the tunnel. A universal joint connects the forward end of the drive shaft to the output shaft of an inboard engine. A control shaft extends from the forward end of the sub-assembly to the exterior of the tunnel. The control shaft may be rotated by a user-controlled actuator to raise and lower the sub-assembly, thereby pre-determining the depth of the propeller. Encounters with submerged objects may also cause the sub-assembly to rotate upwardly to prevent propeller damage.

Abstract: A boat hull having a tunnel structure along the bottom of the hull in the form of a truncated hollow partial cone indentation parallel to the keel of the boat. The tunnel has a truncated end attached to the bottom of the hull near the keel and an open end attached to the transom of the boat. The tunnel encloses a propeller shaft extending from the boat interior at the truncated end, the propeller shaft, a propeller and a rudder. The angle of the cone with respect to the keel places the propeller about 45% to 50% within the tunnel at planing attitude or speed. The combination of the tunnel placement along the hull and the axis of the propeller shaft increases the efficiency of the boat and reduces fuel consumption.

Abstract: A rudder for a water craft is constructed to automatically compensate for impact on the rudder while the craft is maneuvering. The lower portion of the rudder is mounted to an upper portion by a pin. The lower portion can pivot about the pin to reduce drag and draft. The lower portion is spring loaded to return to the original position after impact.

Abstract: A rudder for a water craft is constructed to automatically compensate for impact on the rudder while the craft is maneuvering. The lower portion of the rudder is mounted to an upper portion by a pin. The lower portion can pivot about the pin to reduce drag and draft. The lower portion is spring loaded to return to the original position after impact.

Abstract: A shallow draft sports boat for use in in-shore fishing has a tunnel in its bottom allowing one to place an outboard motor higher with respect to the hull of the boat than is conventional. The tunnel is relatively short with respect to the overall length of the boat, has a small volume and is provided with a recess at its leading end and a vent communicating between the recess and the port in the transom above the water line.

Abstract: A hull for a marine propulsion system includes recesses for receiving and protecting propellers of the propulsion systems. The hull may be designed with a pair of recesses, such as in a stern region, in which props of two separate electrically driven propulsion units are positioned. The recesses are formed integrally with the hull shell, and present open lower and aft regions for free circulation of water displaced by the props. The recesses may also properly orient thrust from the props, such as at oblique angles with respect to a centerline of the hull. The recesses may be formed in the hull for receiving the propulsion units as an optional package. A top surface of each recess forms an integral cavitation plate for reducing or eliminating air entrainment into the water stream around the props as well as cavitation due to localized low pressure regions during operation.

Abstract: The instant invention is directed toward a marine craft having a semi-enclosed surfacing type propeller in a tunnel that draws air through specific areas located and shaped to enhance performance and compensate for prime mover torque and horsepower characteristics. The invention further relates to the field of marine water craft, particularly to high speed power boats utilizing a surface piercing propeller drive system mounted within a propeller tunnel formed integral to the hull of the boat, and most particularly to inclusion, within a wall of said tunnel, of a means for providing air thereto; said means being judiciously placed for linearization of the relationship between vessel velocity and engine speed.

Abstract: The instant invention is directed toward a marine craft having a semi-enclosed surfacing type propeller in a tunnel that draws air through the specific areas located and shaped to enhance performance and compensate for prime mover torque and horsepower characteristics. The invention consists of these air induction features with description of their relationship to craft performance and operating characteristics. This invention also relates certain structures and configuration of these elements, as to enhanced control of said marine craft. The control of these elements having no moving parts or operator interface. Its sequencing is established by the hull movement and the water around it.

Abstract: A boat construction incorporating unique structural features for improved performance at a variety of speeds and water depths. The hull of the boat incorporates a deep-V forward section and a rear tunnel section extending longitudinally rearward from a midpoint of the boat. A vertically adjustable outboard is positioned at the forward end of the tunnel section of the hull. The outboard engine may be vertically adjusted to accommodate different water depths and operational requirements. The engine is positioned within a console above the midpoint for convenient maintenance access and insulation against engine noise. Steering may be accomplished by rotating the engine itself or separately through rudders mounted to the hull. The center mounting of the engine in conjunction with the tunnel section of the hull reduces planing upon acceleration, improves center of gravity and reduces the risk to swimmers and water skiers from a rear mounted propeller.

Abstract: A recess flow plate mounted to a boat hull to substantially cover a through-hull mounting recess located on the bottom of a boat hull is disclosed. The through hull mounting recess has an upstanding front wall which is adapted to receive the propeller shaft and a tapered top wall which extends rearwardly from the upstanding front wall. The flow plate is removably secured over the through-hull recess to maintain the laminar flow of water across the bottom of the boat hull.

Abstract: Several embodiments of watercraft hulls propelled by dual jet propulsion units. The jet propulsion units are either received within a common tunnel or a pair of separate tunnels of the watercraft hull and are moveable for servicing and to bring the jet propulsion units out of the water when the watercraft is not being operated but still is in the body of water.

Abstract: A hull for a water vessel which includes an elongated displacement vessel having bow and stern extremities, a major longitudinal and normally horizontal axis, a vertical and normally perpendicular axis, a length of about L along the longitudinal axis, a propeller mechanism near the stern extremity and a guide vane which is located at a distance of between about 1/4 L and 1/2 L (preferably about 1/3 L) ahead of the propeller mechanism.

Abstract: A boat hull having an underside, a transom and a recess adjacent the transom extending at least partially a transverse dimension or width of the underside. There is also provided a transverse step defining a transverse boundary of the recess as well an internal hollow venting body or reservoir having at least a pair of access ports of restricted cross-sectional size compared with an enlarged cross-sectional area of the venting body. The venting body is in fluid communication with the recess and the hull exterior wherein during travel of the boat hull venting of a low pressure area adjacent the recess can take place without water gaining access to the hull interior in the event of hard turning or rerversing, the water being trapped in the hollow venting body or reservoir.

Abstract: Propulsion for boats (10) by jets of compressed air inside a pair of parallel longitudinal channels (11) open underneath, placed below the hull, substantially horizontal, one on each side of a third wider axial channel (13) suitable for formation, as a consequence of the movement of said boat, of a cushion of air that sustains the hull when sliding over the water.

Abstract: An improved boat construction is disclosed in which a boat, having the typical elongated hull, bow and stern, has a bottom configured as a hydroplane including a transverse step spaced from the bow and stern. A well is provided in the boat bottom and extends from at least the transverse step through the boat stern and receives a powered impeller for engaging and pushing water backwards in a confined flow path within and beyond the well so as to thrust the boat forward. Vertical deflectors are positioned rearwardly of the powered impeller and are attached to the boat in the vicinity of the boat stern for engaging the backwardly moving water in the confined flow path so as to increase or decrease the size of the confined flow path of backwardly moving water emanating from the powered impeller. Immediately forward of the powered impeller in the well is a horizontal deflector which directs more or less water to the powered impeller.

Abstract: A hull for a water vessel which includes an elongated displacement vessel having bow and stern extremities, a major longitudinal and normally horizontal axis, a transverse and normally perpendicular axis, a length of about L along the longitudinal axis, a propeller mechanism near the stern extremity and a guide vane which is located at a distance of between about 1/4 L and 1/2 L (preferably about 1/3 L) ahead of the propeller mechanism.

Abstract: A propulsion system for high-speed powerboats whereby the water level in a tunnel containing a surface-piercing propeller is controlled by admitting external air into the tunnel through an air outlet in the tunnel forward of the propeller. The air is admitted through a duct which has an air intake on the exterior of the boat. The duct may contain a valve which may be opened or closed to control the air supply. Particular configurations of the tunnel and the air supply system are disclosed which maximize the ability to control the water level in the tunnel and the degree to which the propeller is submerged as well as best utilize the configuration of the vessel.

Abstract: A marine drive system includes one or more engines mounted inboard of a boat adjacent the boat transom. The one or more engines are disposed such that their longitudinal axes are substantially perpendicular to the boat centerline and parallel to the boat transom. A drive unit extends substantially vertically relative to each engine during operation. The drive unit preferably includes a drive housing which is mounted to the boat so as to be pivotable between an operating position, in which the propeller is submerged, and an inoperative position in which the propeller is out of the water and the drive unit is disposed at an angle to the vertical relative to the engine. The construction provided by the engine is advantageously employed in a boat hull design in which a pocket is formed in the boat hull, and a portion of the propeller path is disposed within the pocket.

Abstract: A motor-boat hull (10) includes a planing bottom (C) having a V-shaped forward portion, two float-like side portions (14) connected forwardly to the V-shaped portion (12), and a flat recessed aft portion (16) delimited by the side portions (14) and forwardly by a transverse step (18) connecting it with the V-shaped forward portion (12) of the bottom (C).

Abstract: A boat tunnel system apparatus and method for providing shallow operation of a boat when utilizing standard outboard motors. A convex tunnel having a forward end, a convex center section, and a rearward end that exits the stern of a boat above the water line ensures that water adheres to the convex tunnel as the boat moves forward through the water thereby causing water to exit the stern of the boat above the normal water line. As the boat gains speed, water exits higher and higher above the normal water line and, in conjunction with the convex tunnel, a movable motor with propeller attached can be lifted into the solid water stream exiting the stern of the boat. As the boat reaches a plane position, a solid stream of water is provided so far above the normal water line of the boat that the propeller and water intakes of a motor can be raised above the water line and, in fact, raised above the hull of the boat.

Abstract: Improved jet propelled aquatic vessel (1) with a hull (60) profile which increase water entrainment to the jet pump intake orifice (14) and tends to stabilize the vessel. The vessel has a hull (60) with a lowered center section (13) wherein a concave water entrainment groove (15) is located. The vessel includes an operator control panel (43) and an operator support structure (10). The engine (20) is forwardly mounted in a closed engine compartment (21) while the air intake (29) for the engine (20) utilizes a combination of high and low points to avoid flooding of the engine compartment (21) should the vessel (1) capsize. To turn the vessel (1) a jet nozzle (12) is deflected by mechanical linkage (45). The vessel's steering wheel (11) is coordinated with jet nozzle (12) and mechanical linkage (45) to limit maximum deflection.

Abstract: A boat hull having a two-stage flow chamber. The first stage flow chamber starts about amidships as a V-shape fairing upward at a shallow angle and flattening out about halfway to the stern. The second stage flow chamber starts at the end of the forward flow chamber curving upward at a greater angle than the first stage and curving downward slightly at the stern. The second state flow chamber has an inverted V-shape portion connected to the bottom by a pair of narrow sidewalls spreading slightly outward. The forward flwo chamber delivers water to the aft flow chamber free from turbulence. The propeller is disposed in the aft flow chamber and splayed slighly to port. Water exits from the aft flow chamber with minimum turbulence and cavitation.