Abstract: A fish-like underwater robot includes a shell, a driving assembly and an integrated tension and swing component. The integrated tension and swing component includes a plurality of tension ropes and tension elements. Every two adjacent tension elements are connected in series through the plurality of tension ropes. The driving assembly and the integrated tension and swing component are disposed inside the shell. The driving assembly is disposed at a head of the shell. The integrated tension and swing component has an end connected to a tail of the shell and an end connected to the driving assembly. When the fish-like underwater robot is used, the driving assembly drives the integrated tension and swing component to swing to generate power for forward movement. A traditional fish-like tail swing structure is replaced with an integrated tension skeleton structure.

Abstract: The human powered hydrofoil bicycle includes multiple subsystems integrated together including a structural frame subsystem with associated steering and tiller module, a hydrofoil subsystem to provide vehicle lift, and a powertrain subsystem. The structural frame subsystem may be fitted with buoyancy modules to provide the overall vehicle with a near neutrally buoyant character. The structural frame subsystem also supports a seat for an operator and provides structural support for the steering and tiller module for the hydrofoil subsystem and the drivetrain subsystem. The hydrofoil subsystem includes multiple hydrofoil elements at lowermost portions of the vehicle. These hydrofoil elements generally include in a preferred embodiment a larger rear foil and a smaller front foil. The powertrain subsystem generally includes pedals rotatably supported on the vehicle at a convenient location for engagement and driving by feet of an operator.

Abstract: A human propelled watercraft having a pair of flexible fins extending into the water each adapted to oscillate through an arcuate path in a generally transverse direction with respect to the central longitudinal dimension of said watercraft. Pedals are provided for applying input force whereby as input force is applied, the flexible fins can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along the arcuate path. The user can pull a lever and cause the fins to rotate 180° and produce thrust in the reverse direction. The fins are able to pivot and swing aft to avoid damage if there is a collision with a submerged object. The fins are more efficient, durable, and adjustable. Simple plastic roller bearings have been adapted to reduce mechanical friction without the need for oil seals.

Abstract: A watercraft for moving along a direction of movement on water includes a flexible fin with a front face and a rear face to be disposed in the water; and one end of the fin is movable along a line in a reciprocating motion along a direction transverse to the front and rear faces and the direction of movement of the watercraft, causing an opposite free end of the fin to flex back and forth in the water to propel the watercraft in the direction of movement.

Abstract: A device for insertion in watercraft including propulsion means comprising a pair of flappers which oscillate through an arcuate path in a transverse direction with respect to the central longitudinal dimension of the watercraft. As input force is applied, the flappers twist to form an angle of attack for providing forward thrust. The means for applying propulsive force includes a pair of pedals, and further includes pedal cranks operatively associated with the propulsion means, the fore ends of the pedals being pivotally attached to a fixed point.

Abstract: The disclosed invention is directed to a watercraft which comprises at least one main force member attached to at least one wing; the main force member and/or wing and/or a float attached to the wing comprise sufficient displacement to provide flotation for the craft and its payload. Connected to the main force member is a force transmitting member, to which the engine is connected. The engine may comprise a person or another engine (conventional, electronic, wind, etc.). The engine may comprise a weight which undergoes vertical translation, thereby producing the force transmitted by the force transmitting member to the main force member.

Abstract: In one embodiment, a propulsion device for use in a fluid may include a crank-slider mechanism having one or more cranks, one or more connecting rods, a mast, and one or more slide structures. These structures may be arranged so that rotational motion of the shaft is translated to a combination of substantially linear motion of the mast, between an inner extent and an outer extent, and rotational motion of the mast, within an angular range between a first limit and a second limit. A flexible foil may be rigidly coupled to the mast of the crank-slider mechanism. The flexible foil may include a flexible nose portion and a flexible tail portion. The flexible tail portion may have a differing amount of flexibility than the flexible nose portion.

Abstract: An underwater vehicle uses an undulatory fin propulsion system and a control apparatus to receive sensor data and control the operation of the vehicle in real time over a wide range of forward velocities. In an embodiment, a model of propulsive efficiency is used to achieve high values of propulsive efficiency, giving a lowered energy drain on the battery. Externally monitored information, such as that on flow velocity, is conveyed to the control apparatus residing in the vehicle's control unit, which in turn signals the propulsion system to adopt kinematics, such as fin frequency and amplitude, associated with optimal propulsion efficiency. In an embodiment, the model of propulsive efficiency is generated from a multilayer perception neural network model using data from aquatic species, such as undulatory fin propulsion in the knifefish (Xenomystus nigri), and a sensitivity analysis is used to lower the number of required inputs.

Abstract: A human propelled watercraft having a pair of flexible fins extending into the water each adapted to oscillate through an arcuate path in a generally transverse direction with respect to the central longitudinal dimension of said watercraft. Pedals are provided for applying input force whereby as input force is applied, the flexible fins can twist to form an angle of attack for providing forward thrust with respect to the longitudinal dimension of the watercraft while moving in both directions along the arcuate path. The user can pull a lever and cause the fins to rotate 180° and produce thrust in the reverse direction. The fins are able to pivot and swing aft to avoid damage if there is a collision with a submerged object. The fins are more efficient, durable, and adjustable. Simple plastic roller bearings have been adapted to reduce mechanical friction without the need for oil seals.

Abstract: The invention relates to a multidirectional propulsion system for ships, including a mechanical hypocycloid transformer, which comprises a drive system (100) of the mechanical hypocycloid transformer type and which performs two basic functions, namely: generating the oscillating rotational movements of the two concentric shafts (15, 16) in order to move the propeller blades, and rotating integrally about the geometric axis thereof, such that the range of the sweep angle of the swing frames (17, 17?) can be varied gradually between an upper threshold and a lower threshold both when the propulsion system is in operation and stopped. The invention also includes a multidirectional connection system which can change the orientation of the propulsion force of the blades and, consequently, the direction of movement of the ship and which comprises a clutch on each concentric shaft each clutch having two discs. The invention further includes a submerged part, formed by a fish-tail propulsion.

Abstract: An autonomous underwater vehicle (AUV) uses a model of propulsive efficiency to achieve high values of propulsive efficiency over a range of forward velocities, giving a lowered energy drain on the battery. Externally monitored information, such as that on flow velocity, is conveyed to an apparatus residing in the vehicle's control unit, which in turn signals the locomotive unit to adopt kinematics, such as fin frequency and amplitude, associated with optimal propulsion efficiency. In an embodiment, the model of propulsive efficiency is generated from a multilayer perception neural network model using data from aquatic species, such as undulatory fin propulsion in the knifefish (Xenomystus nigri), and a sensitivity analysis is used to lower the number of required inputs. Power savings could protract vehicle operational life and/or provide more power to other functions, such as communications.

Abstract: A ship propulsion system comprising a mechanism to convert mechanical power into a swinging, paddle-like action of a fin-like plate, located at the exterior of a vessel, thereby mimicking the propulsion made by the tail of a fish.

Abstract: A watercraft for transportation and exercise including a boat having an opening therein for permitting a person to be partially below the waterline and partially above the waterline. A sub-frame is operatively attached to the boat, the sub-frame having a lower position and an upper position. A propulsion device is operatively attached to the sub-frame for propelling the watercraft forwardly in response to movement of the person's feet, the propulsion device having a foot contact portion. The foot contact portion of the propulsion device being disposed a predetermined distance from the waterline when using the propulsion device in the transportation mode, said foot contact portion of the propulsion device being disposed in the water and a substantial distance below said predetermined distance when the propulsion device is being used in an exercise mode.

Abstract: The invention relates to a multidirectional propulsion system for ships, including a mechanical hypocycloid transformer, which comprises a drive system (100) of the mechanical hypocycloid transformer type and which performs two basic functions, namely: generating the oscillating rotational movements of the two concentric shafts (15, 16) in order to move the propeller blades, and rotating integrally about the geometric axis thereof, such that the range of the sweep angle of the swing frames (17, 17?) can be varied gradually between an upper threshold and a lower threshold both when the propulsion system is in operation and stopped. The invention also includes a multidirectional connection system which can change the orientation of the propulsion force of the blades and, consequently, the direction of movement of the ship and which comprises a clutch on each concentric shaft each clutch having two discs. The invention further includes a submerged part, formed by a fish-tail propulsion.

Abstract: Non-linear control laws are disclosed and implemented with a controller and control system for maneuvering an underwater vehicle. The control laws change the phase of one Inferior-Olive (IO) neuron with respect to another IO. One control law is global, that is, the control law works (stable and convergent) for any initial condition. The remaining three control laws are local. The control laws are obtained by applying feedback linearization, while retaining non-linear characteristics. Each control law generates a profile (time history) of the control signal to produce a desired phase difference recognizable by a controller to respond to disturbances and to maneuver an underwater vehicle.

Abstract: An apparatus for oscillating and orienting a vane comprising a main lever (7,8) connected to a main pivot (5,6); a main drive linkage (13) adapted to pivot the main lever from side to side about the main pivot in a pivot plane, a vane (16,17) pivotally connected to the main lever remote from the main pivot and adapted to pivot about a vane axis (18,19); an angle change assembly (24,25) adapted to pivot the vane about the vane axis during pivoting of the main lever such that the orientation of the vane relative to a fixed axis in the pivot plane is independent of the orientation of the main lever, the apparatus further comprising a displacement means (20,21) connected to the angle change assembly and adapted such that displacement of the displacement means alters the orientation of the vane relative to the fixed axis.

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: A watercraft propulsion device 10 has a linkage comprising a vertical drive link (20), a support link (12), an upper control link (50) having a forwardly extended handle bar (52), and a lower propulsion link (30) having a horizontal propulsion fin (32) backwardly extended therefrom. The control and propulsion links (50, 30) are interconnected by said drive link (20), which is capable of conveying propulsive oscillatory motion to the propulsion link (30) by means of a linear power actuator (90), and by the support link (12), which is pivotally connected a transom bracket (60) about a substantially vertical axis.

Abstract: Maritime propulsive mechanism employing oscillating fins (4). The mechanism comprises a chariot (3) transferring propulsive power from a source of propulsive power (10) to the fins (4). Oscillating means, driven by a source of propulsive power (10) having a first axis of rotation (17), for oscillating the chariot (3) are provided. The fins (4) are rotatable about a second axis of rotation (6) wherein the first axis of rotation (12) forms an angle ? with the second axis of rotation (6). The fins are connected to the chariot (3) via two connection points (5), (16). The oscillating means can be interposed between two chariots (3), and the oscillating means imparts flywheel-effect on the system. Forces exerted on the chariot transported through the chariot (3), and borne by bearings (9).

Abstract: A robotic architecture for capturing the autonomous performance advantages the animal models enjoy in the natural environment is disclosed. A biomimesis process is employed to allow selective utilization of basic physical components and adaptation of a common control paradigm for each of different vehicle types. The biomimetic architecture involves five functional elements: a basic biomorphic plant for capturing the biomechanical advantages of the model organism; a neural circuit-based controller consisting of a finite state machine; myomorphic actuators producing linear graded force in response to trains of current pulses for mediating movements; labeled line code output by neuromorphic sensors; and a reactive behavioral sequencer executing command sequences defined within a behavioral library.

Abstract: An oscillating-foil type underwater propulsor with a joint provided in the invention, the propulsor including a streamline foil having a foil surface being parallel to a water surface and a span length of at least twice as long as an average chord length of the streamline foil, and a heaving mechanism undergoing heaving motion perpendicular to a propulsion direction of the propulsor and having a transmission section, wherein the transmission section is pivotally connected to the streamline foil to form a joint, the joint being provided at the middle of the span length and having a rotation center located within a circular area, which has a radius of one third of the average chord length and is centered at the point one third of the average chord length ahead of the lifting center of the streamline foil.

Abstract: This invention relates to a propulsion device (12) comprising a flexible fluke (18) that is pivotable about a horizontal axis, for propelling a floating watercraft, said propulsion device (12) being adapted for connection to an output drive shaft (20) that is adapted for transmitting a rotary motion, said propulsion device (12) comprising a fluke oscillation drive (16) having means for gear reduction of the rotary motion transmitted by the shaft (20) and means for converting the rotary motion transmitted by the shaft (20) to oscillatory motion of the fluke (18). The invention further relates to a watercraft comprising such a propulsion device.

Abstract: A pair of foils are pivotably coupled to a nacelle. The nacelle is pivotably coupled to a mast extending down from to a frame and below a water surface. A push rod oscillates, causing the nacelle to experience a heaving motion, in turn causing the foils to flap up and down. The push rod is driven by a power plant such as a human rider. Angles of attack for the foils are actively controlled to optimize lift and propulsion forces provided by the foils to cause the water craft to move over the water. A steering fin is also provided for heading control of the water craft. A control system for separate angles of attack for the foil sends appropriate information to servo motors which cause the foils to rotate relative to the nacelle to achieve optimal angles of attack relative to the particular position of the nacelle at any given moment.

Abstract: An oscillating-foil type underwater propulsor with a joint provided in the invention, the propulsor including a streamline foil having a foil surface being parallel to a water surface and a span length of at least twice as long as an average chord length of the streamline foil, and a heaving mechanism undergoing heaving motion perpendicular to a propulsion direction of the propulsor and having a transmission section, wherein the transmission section is pivotally connected to the streamline foil to form a joint, the joint being provided at the middle of the span length and having a rotation center located within a circular area, which has a radius of one third of the average chord length and is centered at the point one third of the average chord length ahead of the lifting center of the streamline foil.

Abstract: Scuba tank compressed air can now power a dual piston compound motor driving dual water thrusters of a steady pulling underwater propulsion vehicle. Motor exhaust provides diver breathing air through a demand regulator. Motor efficiency allows continual, powerful diver thrust without curtailing normal tank dive time. Lightweight vehicle can be strapped to the scuba tank for “hands free” operation or “diver held” for driving through the water. Diver controls off/on/variable speed with a simple throttle control. Propeller or battery is not required.

Abstract: A marine propulsion system emulates the fishes swimming motion yet is highly maneuverable as it permits changes from forward to reverse motion while underway. In other aspects, the propulsion system may be designed and optimized for efficient human powered propulsion.

Abstract: A sculling boat assembly is provided to control the traveling direction and drive a boat, and the sculling boat assembly installs a transmission mechanism on two hulls, connects an end of each transmission mechanism to a handle extended from the two hulls, connects another end of each transmission mechanism to a paddle rod extended from the tail of the boat, and connects an end of each paddle rod with an extension of a fin-shape member. Through the transmission of each paddle rod, a user applies a force onto each handle to drive the fin-shape member disposed on each paddle rod for the movements of pushing water outward and enclosing water inward, such that the water resistance is converted into a reaction by the soft and hard materials of the fin-shape member and its extension to drive the boat to move forward rapidly.

Abstract: A collapsible watercraft for personal recreation. The collapsible watercraft includes a tubular frame that has a first portion and a second portion. Each of the portions are generally rectangular and are hingably coupled together allowing them to be folded one portion on top of the other. Two sets of pairs of floatation members are hingably mounted to the frame and are positionable between being adjacent the outer side of the frame for use, and adjacent the inner side of the frame for storage or transit. A human-powered oscillation of a fin member propels the craft. The fin member also serves as a rudder for steering. A foldable seat with a backrest along with a cargo net behind the seat is provided. A canopy is mountable to the frame for protection of the user from the elements.

Abstract: An oscillating appendage includes a vessel housing a supply of pressurized fluid with reinforced tubes selectively receiving the pressurized fluid from the vessel, an oscillating valve for controlling the supply of pressurized fluid from the vessel to the reinforced tubes, and a flexible skin encompassing the vessel, the reinforced tubes, and the valve. The flexible skin defines an outer shape of the oscillating appendage with a tail member affixed at a terminal end of the appendage to further propel the appendage by an oscillating motion of the appendage.

Abstract: The structure of a fin shaped soft paddle comprised mainly of: a loom being a hard stick for exerting force; a fulcrum provided on one end of the loom for pivotally connecting to a fixed oarlock socket of the boat; and a fin shaped soft paddle blade made of elastic material with an end connected with the fulcrum. When in rowing to move the boat forwardly, by having the difference of softness and elasticity on various areas and the bendability of the paddle blade, the resistance of the water flow and the vector offsetting the forwarding force are reduced to the minimum, so that a user can move forward the boat with a most economic mode and with simplest and most force saving motions.

Abstract: This invention is an improvement of a prior invention which is a small watercraft propelled by a vertical fin-like device and/or a sail. The prior invention has a vertical shaft located in the front portion of the watercraft. Multiple foot-operated arms are secured to the upper portion of the shaft. A fin is secured to a hinge which is located at the trailing end of an elongated member. The leading end of the elongated member is removably secured to a joint device at the lower end of the shaft. The arms, shaft, elongated member, and fin can rotate 360 degrees about the shaft axis. An opening between the shaft and the operator is provided to allow the elongated member together with the fin to be secured and removed during operation. A post is secured to the upper end of the shaft. The post allows a sail mast to telescope on and the turning of the post does not affect the mast or vice versa. The prior invention also has a hand-controlled rudder at the rear end of the watercraft.

Abstract: This invention is an improvement to a prior invention—Small Watercraft with Fin and Sail. The improvement consists of the introductions of a rotatable water-foil means, a fin lock/release mechanism, fin rotation stoppers, rear vertical fins, end floats, and a jig/mast. The rotatable water-foil means covers a portion of the elongated member and is rotatable about the centerline of the covered portion of the elongated member. The fin lock/release mechanism installed on the elongated member consists of a wire travelling and movable along the elongated member. A vertical pin-like means is secured at a lower end of the wire. The vertical pin-like means can only move toward or away from a lower end of the elongated member. The fin rotation stoppers consist of two members. Each of the members has one end connected to the elongated member and the other end connected to the leading edge of the fin. One or more vertical fixed fins are added to the rear portion of the watercraft.

Abstract: A sportboard device (10) for movement over a fluid medium, including water, snow, or ice; including a plurality of pivotable fin assemblies (20) for transferring force from the user's feet to the fluid. Fin assembly (20) includes foot platform (30), transmission shaft (51), and fin (21). User stands on foot platforms (30) with feet secured by strap (34), binding (35), or friction surface (36). Twisting the feet pivots foot platforms (30). Torque is transmitted through shaft (50) to fin (21), causing fin (21) to pivot against the fluid medium. Coordinated movements of foot platforms (30) cause sportboard (10) to move relative to the fluid in the absence of gravity, wind, or wave force or in a direction different from that of the natural force.

Abstract: A swim fin assembly of a generally T-shaped configuration including a flexible fin and an elongated foot support bar traversing and being operatively connected to the fin in a rigid securement. The fin is progressively more flexible from its forward end to its rearward end and from its upper and lower edges toward its center. A pair of foot receiving members are pivotally mounted on the foot support bar proximate its extended ends such that upon securing one's feet in the foot receiving members the fin is substantially perpendicular with respect to the wearer's feet such that upon exerting a stepping-type motion employing alternating thrusts in a prone position in a body of water, the resulting reciprocal pivotal movement of the foot support bar about its midpoint causes the vertically oriented fin to move from side-to-side and propel the wearer through the water.

Abstract: A diver lying prone in the water grasps the invention with his hands and pushes on pedals with his feet. The pedal motion is converted into propulsive force that moves the diver through the water. The diver is free to bend at his hip joints and bend and twist his spine to cause turns, dives and ascents in the water. The preferred embodiment of the propulsion means comprises a simple direct drive of an arm. As the diver operates the pedals the forward end of the arm pivots with respect to the device as the rearward end of the arm sweeps back and forth in the water. A fin is attached to the rearward end of the arm. The fin is fitted with a simple device for controlling the angle of attack of the fin with respect to the flow of water past it.

Abstract: A water vehicle includes at least first and second foils which are at least partially submersible in water. These foils are movable, at least to a limited extent relative to each other. Repeated movement of the foils generates a propelling force that will move the water vehicle on the body of water.

Abstract: A submersible vehicle is a type having swinging wings. The vehicle is provided with a vehicle main body, a plurality of swinging wings provided for the main body and arranged in series, rotatable shafts located at front edges of the swinging wings, respectively, actuators for driving the shafts independently of one another, and a wing controller for controlling the actuators in such a manner that the wings enable to swing in a flexible manner like the tail fin of a fish, thereby producing a desired propelling force and performing a steering operation.

Abstract: A small watercraft, e.g. a small catamaran, propelled by a vertical fin-like device and/or a sail is invented. A vertical shaft is located in the front portion of the craft. Foot operated multiple arms are secured to the upper portion of the shaft. The fin is secured to a hinge which is located at the trailing end of an elongated member. The leading end of the elongated member is removably secured to a joint device at the lower end of the shaft. The arms, shaft, elongated member, and fin can rotate 360 degrees about the shaft axis. Depending on the general direction the elongated member is pointing to, the fin can propel and turn the watercraft. Because the shaft can rotate 360 degrees, the craft can also go backwards and turn at the radius less of its length. An opening between the fin and the operator is provided to allow the fin to be secured and removed during operation.

Abstract: A combination bicycle and boat has a frame; a buoyant rear wheel; and a buoyant front wheel driven by a pair of pedals. The frame is a rigid construction that supports the user on the front and rear wheels for mobility. The frame has a seat and rotatably mounted handle bars, and is preferably shaped to resemble an animal having a head and a tail. The combination preferably further includes a water gun powered by a water pump; and the water gun works in conjunction with a water sensing fan to facilitate a game of water tag. The invention further includes a manually propelled animal boat. The animal boat has a frame having an animal shape having a head and a tail. The animal boat has a crank is located near the head operably engages with a propeller shaped like an animal flipper located near the tail.

Abstract: A muscle-powered watercraft includes flotation and propulsion structure having at least two blades which remain rigid under the stresses that are subjected to. The front edges of the blades are hinged about respective axes transverse to the watercraft's axis of propulsion, spaced from one another along the axis of propulsion on either side of the watercraft's center of gravity. Each of these blades extends symmetrically from the axis of propulsion. Abutment structure limits the angle of freedom of each blade about its hinging axis, and the volume of water displaceable by immersion of the flotation structure is selected to correspond to 1 to 2 times the total laden weight of the watercraft. The flotation structure has feet-supporting surfaces distributed about the craft's center of gravity, whereby a driver may impart to the watercraft a sinusoidal movement in and out of the water by pitching the craft and hence making the blades operate in opposition to one another between the abutments.

Abstract: A propulsion system for use in a fluid, the system utilizing at least one foil which is both oscillated at a frequency f with an amplitude a in a direction substantially transverse to the propulsion direction and flapped or pitched about a pivot point to change the foil pitch angle to the selected direction of motion with a smooth periodic motion. Parameters of the system including Strouhal number, angle of attack, ratio of the distance to the foil pivot point from the leading edge of the foil to the chord length, the ratio of the amplitude of oscillation to the foil chord width and the phase angle between heave and pitch are all selected so as to optimize the drive efficiency of the foil system.

Abstract: A propulsion device for a floating structure, especially a watercraft, includes an essentially horizontally disposed wing which is rotatably connected to the craft and is arranged to carry out a tilting movement and provide for propulsion of the craft by relative vertical movement between the wing and the surrounding water. The wing is mounted in such a manner as to be capable of turning 360.degree. about its tilting axis, the tilting axis being located at or somewhat ahead of the balance point for lift of the wing, as viewed in the horizontal direction in which the craft is moving. A system for returning the wing towards a neutral horizontal position after the wing has angularly deviated therefrom includes a control system which, based upon a signal received from a position detector, controls a motor that exerts torque on the wing in the direction towards the neutral position.

Abstract: A small self-propelled watercraft having a main hull and an outrigger hull that is powered by a fin like oar arrangement. The main hull seats the rider and provides the substantial portion of the buoyancy for the watercraft. The fin like oar arrangement includes a blade type fin that is supported for pivotal movement at the end of the oar and the degree of pivotal movement can be adjusted from the handle end of the oar. In addition, the fin like blade is supported for movement between forward and reverse thrust positions and this movement is also controlled at the handle of the oar.

Abstract: A self-propelled boat (10) to be used by a boater to maneuver himself along the surface of a body of water, especially in shallow water where the use of a motorized boat or a deep bottom boat is impossible or otherwise impractical. The self-propelled boat (10) includes a body (12) to carry the boater and provide buoyancy. A seat (14) is provided on which the boater may be seated, the seat (14) being provided with a position adjuster (88) for fixing the seat (14) at selected positions along the longitudinal axis of the boat (10). A propulsion system (16) is provided such that the boat (10) may be maneuvered along the surface of the water. The propulsion system (16) includes a pair of foot mounts (146, 148) for engaging the feet of the boater to oscillate selected cords (132L, 132R, 138), the cords (132L. 132R, 138) being connected such as to form a loop. Bow and stern pulleys (98, 106) are provided for holding the cord (132) in place.

Abstract: A water-borne vehicle with floats, a frame which is mounted on the floats providing a seat and a steering mechanism, and a propulsion means for propelling the vehicle in the water. The propulsion means comprises a plate which is generally parallel to the surface of the water and which is displaced up and down by a foot pedalled crank. A connecting arm is attached at one end rigidly and perpendicularly to the plate and at the opposite end to the crank. The horizontal position of the plate is maintained by an upright member which is slidably retained between rollers that maintain its upright position and is pivotally attached to the plate. As the crank is rotated, one end of the connecting arm follows a circular path, displacing the plate upward and downward. As the plate oscillates up and down, the upright member slides up and down between the rollers and maintains the horizontal position of the plate as directly below the upright member.

Abstract: A rocker type propulsion mechanism for a boat includes a rocker arm pivotally provided on the boat, a lever arm being laterally connected to the rocker arm for rockably actuating the rocker arm, a paddle being pivoted on an other end of the rocker arm, and a blocking device being provided beside the paddle for limiting a rotation of the paddle. A rotation of the rocker arm causes the paddle to make a relative movement with water in order to propel the boat.

Abstract: A man-powered boat propulsion device comprising a hand rod reciprocated horizontally by rowers, a vertical support rod moveably suspended from and slidably supporting the hand rod on a sliding support, an operation rod pivoted to the hand rod, a vertical shaft interlocked with the operation rod and capable of rotating clockwise and counter-clockwise, a fin blade secured to the shaft and capable of horizontally rotating both rightward and leftward alternately, a handle a connected to the hand rod, a change-over device connected to the handle and capable of transmitting a turning movement of the handle either clockwise or counter-clockwise changeably, and a direction control device connected between the change-over device and the shaft for transmitting the handle turning movement. Easy boat propulsion and steering is possible even of unskilled persons.

Abstract: A propulsion system for a water-borne vessel. There is a generally inflexible fin member. A projection member is connected to the vessel. It has a resilient connecting member attached to the generally inflexible fin member. The projection member is connected to the vessel so as to be held below water along an axis parallel to the water line.

Abstract: A boat propulsion apparatus having a thrust blade mounted for swinging movement about a generally horizontal swing axis lengthwise of the boat and for turning movement about an upright blade axis, and a swash plate drive for simultaneously swinging the blade about the swing axis in a direction crosswise of the boat and for angularly oscillating the blade about the blade axis to sinusoidally vary the pitch of the blade as the blade is swung crosswise of the boat. A planetary gear type mechanism is provided for adjusting the angle of the swash plate while the boat propulsion apparatus is in operation or when it is stopped. The thrust blade is connected to the blade shaft through an overload release coupling to prevent damage to the thrust blade and propulsion apparatus in the event the thrust blade strikes an obstruction. An improved arrangement for mounting the thrust blade on the swing shaft and for sealing the thrust blade to an enclosure for the boat propulsion apparatus, is also disclosed.

Abstract: A water craft includes a pair of spaced buoyant panels mounted to a substantially H-shaped frame. A pair of fins mounted along a central longitudinal member of the frame between the panels provides propulsion and steering control. Propulsion is maximized by means of a combined cam, linkage and telescoping support structure that varies the length of the aft fin so as to oscillate the fin in a substantially figure eight path. Further, the rigidity and flexibility of the fin may be controlled through a tension cable and hand actuator.