Abstract: A curved body (830), for propelling fluids, crafts and harvesting fluid power, comprises a convex outer leading surface securely connected to a concave inner trailing surface to define an open vessel. Upon oscillation, ambient fluids are accelerated and ejected from the vessel to propel the vessel and the ambient fluids in opposite directions. Apparatus is secured to a motive power source directly or via actuating member (832), by fastening through aperture (834). The oscillating propulsor can be operated directly by a reciprocating motive power source, and indirectly by the reaction momentum imparted to a supporting base. Thrust may be vectored by rotation of the curved body (830) about the supporting base. Drag reduction using fluid dynamic shapes, intake openings, a fore fin (844), an aft fin (846), and a lubricant cavity, are embodied. Enhanced propulsion using multistage oscillating propulsors is embodied.

Abstract: A water vehicle moving on or in a liquid and including a flotation element (1) that is connected by a connection member (6) to a carrier (3), the water vehicle being characterized in that the connection member (6) is shaped so as to enable the carrier (3) to assume at least two positions, namely:—a raised position where the longitudinal axis of the carrier (3) and those of the flotation element (1) substantially extend into the same horizontal plane, the carrier (3) then being on the surface and capable of making up a central shell; and—a lowered position where the carrier (3) extends under the plane including the longitudinal axis of each of the flotation element (1), the carrier (3) then being submerged.

Abstract: Human powered watercrafts, propulsion devices, and propelling methods are provided. A watercraft having a deck is configured with a first rocker having graspable input arm above-deck and a lower output arm, the first rocker being pivoted to the craft, the output arm connecting a push-bar at a first end and the push-bar having a second end connecting a second rocker, the second rocker having input and output arms, the output arm of the second rocker having a propelling fin, the second rocker being pivoted to the watercraft. The watercraft may have a third rocker, fin, and pivot, and more. Users stand upon deck, grasp the first rocker's input arm and vertically thrust the rocker to propel. The invention further comprises a device for human powered propulsion remove-ably attachable to watercrafts, especially small boats, and surfboards, and for propelling them from a standing position by human power.

Abstract: Human powered watercrafts, propulsion systems, and methods of propulsion are provided. A watercraft having an upper deck is configured with a cam plate having a pedal above the deck and a plate and cam below the deck, the cam engaging a cam follower of a fin bar, the fin bar having a substantially vertical propelling fin at an aft end and a pivot to the craft at a forward end. In another embodiment the craft receives two cam plates with pedals, a plurality of fin bars and two propelling fins, all operatively interconnected by a pulley and belt such that a leg thrust upon a pedal opens the fins and an opposite leg thrust upon the opposing pedal closes the fins, propelling the craft. In still another embodiment, an open, hollow surfboard remove-ably receives the propulsion system and a user activate-able buoyancy compensator making a submersible human powered watercraft.

Abstract: Human powered watercrafts, propulsion devices, and methods of propulsion are provided. A watercraft having an upper deck is configured with a cam plate having a pedal above the deck and a plate and cam below the deck, the cam engaging a cam follower of a fin bar, the fin bar having a substantially vertical propelling fin at an aft end and a pivot to the craft at a forward end. In another embodiment the craft receives two cam plates with pedals, a plurality of fin bars and two propelling fins, all operatively interconnected by a pulley and belt such that a leg thrust upon a pedal opens the fins and an opposite leg thrust upon the opposing pedal closes the fms. Another embodiment, an open, hollow surfboard receives the propulsion device and a buoyancy compensator making a submersible human powered watercraft which may be propelled upon and beneath the sea.

Abstract: A water sport device that enables a person to walk upright over the water consists of a boat-shaped lower part and an upper part between which a chamber is formed whereby the chamber has an inlet and opens out into an outlet. A drive mechanism actuated with the feet comprises two treadles that can be moved up and down, a propeller in the chamber that can be rotated on a vertical axis and the means for transforming the up and down movement of the treadles into a rotational movement of the propeller. The means preferably comprise a bevel gear and two free-wheel bearings.

Abstract: A device for propelling a personal watercraft comprising a base having an inner channel and an outer channel. A fin is disposed substantially adjacent to the base and is rotatable relative to the base. The fin has an inner protrusion adapted to moveably engage the inner channel, and an outer protrusion adapted to moveably engage the outer channel. A yoke is disposed substantially adjacent to base and adapted to engage the inner protrusion. When a force is applied to the yoke along a first vector, the inner and outer protrusions move in reciprocal directions causing the fin to rotate.

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 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 watercraft propelled with tread force includes a buoyant hull. A seat unit is mounted on the hull. A propulsion device is arranged to propel the hull. A manually operated apparatus is arranged to power the propulsion device. The manually operated apparatus is disposed in front of the seat unit and comprises a slide mechanism that includes a pair of pedals slideable with tread force alternately given to each one of the pedals by a rider in the seat unit.

Abstract: A boat having a helical drive mechanism. The helical drive mechanism includes a slider engaged with a twisted screw or a cylinder having a helical slot or groove. The helical drive mechanism is connected to a force input shaft which is arranged within the boat so that it can be driven by the user's feet or hands. The user drives the force input shaft in a rectilinear motion to force the twisted screw or cylinder of the helical drive mechanism to rotate. This force is ultimately transferred to a propeller to move the boat.

Abstract: A pedal-powered boat that uses a flexible shaft to drive a propeller. By using a flexible shaft, the user's seat can be placed lower in the vessel, thereby increasing stability. The device also uses a pair of foot pegs and a ratcheted straight driver, which eliminates standard pedals, with their sweeping circular motion. This straight drive not only increases the efficiency of the leg power, it also converts the rotary action of the pedals to a linear motion that reduces the amount of space required to operate the unit. Thus, the driver unit can be placed under a seat so that it does not excessively intrude into the space of the boat.

Abstract: A new and improved leg assisted forward rowing system wherein a user can mechanically advantage the rowing of a boat by first pushing his foot forward along a foot glide member which is slidably engaged within a first track member. This force is transferred to the oar via a pulley belt system that engages both the foot sliding mechanism and an oar movement mechanism. The oar movement mechanism comprises an oar glide member that is forced by the pulley belt system to slide within a second track member in the opposite direction of the foot sliding mechanism. Attached to the oar glide member is an oar support mechanism in which the handle of an oar is received within an oar lock having a downwardly extending stem. The oar lock stem is slidably received by a stem support member that allows the stem to slide upward and downward therein. Additionally, the oar lock is dimensioned to allow movement of the oar handle; however, this movement may be controlled/restricted by the insertion of filler material (i.e.

Abstract: There is provided an apparatus for propelling a water vehicle. A plurality of rotatable paddles are mounted on a pair of spaced apart slidable slide mechanism. The slide mechanism are moveable within a pair of channels formed on opposing sides of a frame. The slide mechanisms are connected to rowing handles and/or foot pedals for providing power. The paddles are rotated down during the power stroke and are rotated up while returning to the initial position. The apparatus may be used to retro-fit an existing water vehicle or may be an integral part of a water vehicle.

Abstract: An apparatus for forward facing rowing of a boat is disclosed. An elongate outrigger support extends outwardly from a mounting point in the boat and has an end adjacent to the mounting point around which the elongate outrigger support pivots horizontally. An outrigger support and handle connector sleeve is slidably mounted over the elongate outrigger support. An elongate handle is pivotally connected to the sleeve to allow the elongate handle to pivot relative to both the sleeve and the outrigger support. A handle and oar connector attaches the outboard end of the elongate handle to an oar within the midsection of the oar. A rotation transfer mechanism in the handle and oar connector causes corresponding rotation of the oar upon rotation of the elongate handle. The handle and oar connector transfers, from the elongate handle to the oar, pivotal and rotational movement as the elongate handle rotates, as well as moves along and pivots around the elongate outrigger support.

Abstract: A recreational water craft is propelled by an individual using cross country skiing action. The weight of the operator is supported on a platform between two parallel floats thus providing a stable craft. The water craft comprises two longitudinal floats with a connecting frame, a first guide rail is mounted on the connecting frame having a first foot supporting trolley constrained to move backwards and forwards on the first guide rail, a second guide rail substantially parallel to the first guide rail mounted on the connecting frame, having a second foot supporting trolley constrained to move backwards and forwards on the second guide rail, a propulsion arrangement for moving the craft through the water when the first trolley or second trolley are moved backwards and forwards on the first or second guide rails, and a steering arrangement to direct direction of movement of the craft through the water.

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 machine powered by forces exerted by the machine user on machine driving members, such as pedals, which drive a rotary driven member through a unique variable ratio drive system. The machine may be constructed and arranged for use as either a vehicular conveyance for the machine, user or a stationary exercise machine both of which operate in a manner that provides an effective therapeutic exercise for certain orthopedic problems, particularly spine and leg problems. A drive system for the machine and other uses.

Abstract: A swimming frame for competition in swimming, swimming instruction, muscle strengthening, and entertainment in the water comprises a pair of floats (1), a clamping unit (2, 3), and a paddle unit (4, 5, 6). It might be used by everyone regardless of the ability to swim. The paddle unit might by modified giving an additional possibility to practice butterfly-like and crawl-like style of swimming. A swimmer being clamped between rigid (2) and flexible (3) portion of the clamping unit is producing the push-pull movements of the paddle unit. When he pushes the unit, the paddle (4) is rotated up to horizontal position by the water pressure against its front. When he pulls the unit, the paddle is rotated up to vertical position by water pressure against its back. Because of the difference in the paddle hydroresistance between push and pull movements the swimming frame will be propelled by the swimmer.

Abstract: On the vehicle are mounted an actuation member, a force transmission unit and a drive element. Preferably, the actuation member is comprised of two levers, each of them being fixed to a metal cable each connected to a chain, the two chains actuating the wheels of a gear-box. The latter acts on the drive element which sets in motion the vehicle. A sliding seat enables to transmit the maximum of muscular power to both levers. One or a plurality of free wheels transform the reciprocating motion of the levers into a unidirectional motion for the drive element. With this vehicle, it is possible to optimally transform the muscular energy into driving power.

Abstract: This device is for aiding a swimmer to obtain more thrust when swimming underwater. Primarily, it consists of a pair of poles secured to a harness, which is worn by the user. It also consists of a plurality of pivotal fins secured to the harness, for increasing the speed of the user, who moves the device by a pair of handle grips secured to the poles.