Abstract: A displace hull with a shape that is both laterally symmetric and fore-to-aft symmetric is disclosed. The hull includes a pair of channels that help to manage a flow of water around the hull. The hull also includes sponsons and propellers that are located amidships on the port and starboard sides.

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 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: A marine vessel comprising: at least one buoyant tubular foil; at least one venturi injection ring positioned adjacent to the perimeter of the at least one buoyant tubular foil so as to create a passageway between the at least one venturi injection ring and the perimeter of the at least one buoyant tubular foil, wherein the passageway is characterized by a fore opening, an aft opening, and an intermediate opening disposed between the fore opening and the aft opening, and wherein the intermediate opening is smaller than the fore opening and the aft opening; at least one fluid opening formed in the perimeter of the at least one buoyant tubular foil adjacent to at least one of the intermediate opening and the aft opening; and at least one passageway connecting the at least one fluid opening to a source of fluid.

Abstract: In a thruster for a vessel including a hull, the thruster comprises at least one tunnel element and at least one thruster unit. The tunnel element includes at least a part of a through tunnel in the hull when arranged in the hull. The at least one thruster unit and the at least one tunnel element include cooperating fastening devices for detachably fixing the at least one thruster unit in the at least one tunnel element such that the at least one thruster unit is configured to be passed through the tunnel and mounted to the at least one tunnel element, or demounted from the at least one tunnel element and passed out of the tunnel. A method for mounting and demounting a thruster in a tunnel element includes a tunnel element arranged in the vessel of a hull.

Abstract: In a thruster for a vessel including a hull, the thruster comprises at least one tunnel element and at least one thruster unit. The tunnel element includes at least a part of a through tunnel in the hull when arranged in the hull. The at least one thruster unit and the at least one tunnel element include cooperating fastening devices for detachably fixing the at least one thruster unit in the at least one tunnel element such that the at least one thruster unit is configured to be passed through the tunnel and mounted to the at least one tunnel element, or demounted from the at least one tunnel element and passed out of the tunnel. A method for mounting and demounting a thruster in a tunnel element includes a tunnel element arranged in the vessel of a hull.

Abstract: The instant invention is a shroud/keel/rudder combination for use on a engine driven marine vessel having a vented tunnel propulsion system. The combination produces acceptable acceleration, minimal loss of speed, resistance to weed entanglement and optimized steering, in both forward and reverse, especially when used with surface piercing propellers.

Abstract: An apparatus for providing thrust adjustment on an underwater vehicle with a propeller shroud is disclosed. A portion of the vehicles body is provided with a compliant surface such that expansion and contraction of the compliant surface affects the flow of water through a channel formed by the vehicle body and the propeller shroud, resulting in variable thrust on the vehicle.

Abstract: A system and apparatus for providing integrated boat thrusters which eliminates interfering with the integrity of the hull, and undesirable drilling and cutting of the hull to accommodate separate glass tubes or pipes that are conventionally used to form thruster tunnels. The instant system provides integrally molded thruster tunnel sections within the hull, and unique keystone inserts which are complementary to the molded thruster tunnel sections and complete the water flow chambers through the hull about the propellers. Separate tubes are not utilized. Thruster motors and mounting mechanisms are securely fastened in flat planes enhancing strength, performance and maintenance of the assemblies. In a preferred embodiment, the keystone insert is generally wedge shaped to provide a secure fit and bond within the molded tunnel section having angled walls.

Abstract: The ship body of the present invention comprises at least two levels. One is an upper level that comprises a floatable body. The other is a lower level. The lower level is intended to be submerged under water in normal use. The lower level comprises at least two parallel, essentially vertical walls, a floor, and a ceiling connecting the at least two parallel essentially vertical walls. The front end and a rear end of the lower level are open to allow water to enter through the front end and exit through the rear end of the lower level.

Abstract: Enhanced watercraft performance is provided by combinations of one or more inboard swivel propulsion drives and hull tunnels. A tunnel at the hull centerline with specific features provides performance advantages for a center swivel propulsion drive. Use of front propeller based traction propulsion is particularly advantageous in the swivel drive systems and allows the use of tunnels with improved tunnel conformations. Advantages of the traction swivel drive arrangements include minimization of hull space with smaller engine room volume, greater propulsion efficiency and improved watercraft handling.

Abstract: The present invention relates to a method and an auxiliary device in connection with disassembly and/or assembly of a tunnel thruster unit by use of the auxiliary device (1) to guide the thruster unit (2) and its movement during disassembly/assembly inside the tunnel (4), the thruster unit (2) thereafter being led away through the tunnel (4), said auxiliary device (1) being removably fixed at the thruster unit (2) before final disassembly, such that the auxiliary device (1) controls the movement during disassembly/assembly, mainly by compressive forces.

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: The present invention relates to improving the structure of the ship by means of fitting plural screws in series on the identical shaft generated by the diesel engine to augment the velocity in proceeding operation and bifurcating the bottom of said ship to reduce the water pressure on the prow thereof.

Abstract: The invention relates to a watercraft, particularly a river boat, with a hull for receiving useful devices and with propulsion units for generating a driving force and which are located on the hull. The watercraft according to the invention is characterized in that guiding elements are provided in the bow area on the underside of the hull, which have a vertical, forwardly tapering wedge shape, that the propulsion units in the bow area are set back from the wedge-shaped guiding elements, that between the guiding elements is provided a partial area of the hull constructed in the form of a horizontal wedge and that the propulsion units are pivotably mounted.

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 propulsion system for a watercraft includes a concavity formed in a hull of the watercraft. The concavity has a minimum depth at its leading end and a maximum depth at its trailing end. An impeller is mounted in the trailing end of the concavity and a stator trails the impeller. A nozzle having a radius only slightly less than a radius of the impeller is disposed in trailing relation to the stator. An elongate drive shaft extends from an engine mounted fore of the concavity to the impeller. An intake grate is disposed in a mouth of the concavity. Water flowing through the intake grate flows through the concavity in a laminar flow and encounters no obstacles other than the elongate drive shaft before encountering the impeller.

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 modified boat hull, providing for dual, non-ventilating aft thruster tunnels. Each tunnel includes a generally tubular section which fluidly communicates with the transom outlet orifice, and a converging transition section which communicates at the extreme opposite end with a water inlet orifice which is positioned within an enhanced, vertical strake surface. The vertical strake surface is located beneath the chine of the boat, as well as beneath the water line. The modified hull also includes an inboard offset for the vertical strake surface, and a chine step to enhance hydrodynamic performance of the hull when attempting to achieve or exceed plane speed.

Abstract: The stern unit (1) provides the movement and the steering of the marine craft. The stern unit (1) comprises a casing (2), a shaft (3), a shaft housing (4), water lubricated bearings (5), propeller (6), rudder (7), a rudder-stand (8) and a hydraulic piston (10). The stern unit (1) contains a fish-back shaped casing (2) acting as a tunnel and a propeller (6) near the outlet of said casing (2). The propeller (6) is connected to the inboard engine mounted in the marine craft, in a straight line by means of the transmission mechanism, using a shaft (3) borne in the shaft housing (4) and water bearings (5) without using any spiders and balls. The rudders activated by means of a hydraulic piston takes place in front of the propeller enable the marine craft to be guided.

Abstract: A bottom assembly for motor boats is described, of the type including at least one longitudinal tunnel, through which passes a propeller shaft exiting from the bottom, wherein there is provided at least one ground wall to close, totally or partially, the tunnel and limit the entry of water into the same during boat advancement.

Abstract: A bottom assembly for motor boats is described, of the type including at least one longitudinal tunnel, through which passes a propeller shaft exiting from the bottom, wherein it is provided at least one ground wall to close, totally or partially, the tunnel and limit the entry of water into the same during boat advancement.

Abstract: A propulsion and steering system for reducing water mounding along and under a bow and hull of a mono-hull ship thereby enhancing displacement of water by the hull and permitting increase of the beam to length ratio of the ship comprising two or more thrust chambers, each of the thrust chambers passing lengthwise through the hull below a waterline of the ship, each of the thrust chambers having an open bow end and an open stern end, and a bow of the ship configured to channel water into the bow ends of the thrust chambers. Preferred configurations of the bow are disclosed. A propeller or turbine thruster is preferably positioned in each of the thrust chambers for propelling water through the thrust chamber.

Abstract: An improved method for raising a propeller up into the hull of a marine water craft for the purpose of reducing the likelihood of underwater impact and improving shallow water operation without encountering the high efficiency losses normally associated with shallow draft drive systems or water jets. It utilizes a unique tunnel which is open bottomed and extends longitudinally in the running surface of the hull. The lead in to the tunnel, which is termed the “chute” forms the entry to a deeper portion of the tunnel located further aft. A super-cavitating propeller is positioned in the aft tunnel section. The propeller is raised vertically into the tunnel such that the propeller blade tips can be above, below or flush with the running surface of the hull but the prop shaft is always above the running surface of the hull. The invention relates to the longitudinal position of the chute with respect to the propeller, the general shape of the chute and its normal method of operation.

Abstract: The present invention relates to a canoe that is propelled by a motor. The motor having a shaft and a propeller contained within a hydrodynamically designed housing. The housing further having an inlet and an outlet whereby when the propeller rotates producing thrust, water enters the inlet and is thrust outwardly from the outlet.

Abstract: A sailboard has a hull (10) which is of smooth rounded elongated shape of little depth and tapers down in width and in depth from its middle region to its ends. The hull has an overall length from to five times its width and has an enclosed air passage along its underside extending longitudinally for at least a part of its length from a front air inlet opening (14) to a rear air outlet opening (16).

Abstract: A full or partial tunnel wedge is positioned in the propeller shaft tunnel ft of the propeller on a waterborne craft. The size and angle of the wedge is determined by the characteristics of the particular craft. The wedge converges water flow and increases water pressure aft of the propeller. The higher water pressure increases the propeller thrust and reduces the hull drag of the propeller shaft tunnel thus reducing the shaft horsepower required to maintain a given speed.

Abstract: A thrust tube propulsion system for cargo vessels is disclosed. The propulsion system is incorporated beneath typical cargo vessel hulls by placing in the hull power equipment and by placing below the hull a plurality of longitudinally extending thrust tubes integrally affixed to the hull. Propellers are located within the thrust tubes at approximately the midpoint thereof to propel the vessel.