Abstract: A catamaran design has a third hull positioned between the conventional hulls. The third hull has a length equal to about two-thirds of the length of the conventional hulls, and a recess is formed in the underside of the deck aft of the third hull. The recess has a depth sufficient to accommodate the rooster tail created by the third hull. The third hull enhances the buoyancy of the craft and prevents formation of waves under the leading end of the deck. The recess prevents the rooster tail from impinging against the underside of the deck. The third hull produces a concave wake and it is submerged to a similar extent as the twin hulls when the watercraft is at rest floating in a body of water. In combination, the third hull and recess provide a catamaran that can handle heavy seas, with control and safety, that is not subject to the pounding of waves on the underside of its deck, and which performs in all other respects like a conventional catamaran.

Abstract: A jet ski hull has a lower section formed with a pronounced and sharp leading keel portion defined by oppositely disposed curvilinear fluted side walls extending downwardly from the peripheral edge. The leading keel portion expands outwardly to define a central longitudinal flat bottom which divides each of the fluted side walls. A fluted longitudinal groove is formed along the outer edge of each of the fluted side walls, starting approximately at a point rearward of where the leading keel begins to flatten out.

Abstract: Fluid friction of a body moving through air or water is reduced by means of a plurality of symmetrical depressions on the surface of the body. The symmetrical depressions are closely spaced but not quite abutting. The symmetrical depressions are sized in proportion to the width of the body. For a cylindrical body, each symmetrical depression is between one fiftieth and one fortieth of the diameter of the body. The symmetrical depressions are shallow, ten to twenty times wider than they are deep. The symmetrical depressions are shaped like sections of truncated cones, or hexagonal prisms, or geodesic domes. The symmetrical depressions cover virtually the entire surface of the body.

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: The marine hull has a forebody, a transom, and a bottom extending therebetween having pairs of upwardly formed channels between the forebody and the transom. The channels of each pair diverge rearwardly. Fluid flow exit paths interrupt the channel walls so that fluid from some of the channels can flow laterally outwardly, and the rear ends of at least some of the channels open at a peripheral edge of the bottom whereby water in these channels is free to discharge in both a rearward and laterally outward direction.

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: Hydrofoil craft, particularly a method of economically modifying a conventional hull by means of foils to obtain enhanced lift and rough water stability. The method is characterized by defining an axial tunnel(s) intermediate the bow and transom of a catamaran hull or V-bottom hull modified with chine mounted aerofoils; positioning a flexible dihedral foil beneath the water line and on either side of the bow so as to obstruct and create a turbulence in the forward end of the tunnel, while cushioning shock and lifting the bow; and simultaneously enclosing the transom end of the tunnel with a foil, so as to compress the turbulence and lift the transom.

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: Hydrofoil craft, particularly a method of economically modifying a conventional hull by means of foils to obtain enhanced lift and rough water stability. The method is characterized by defining an axial tunnel(s) intermediate the bow and transom of a catamaran hull or V-bottom hull modified with chine mounted aerofoils; positioning a flexible dihedral foil beneath the water line and on either side of the bow so as to obstruct and create a turbulence in the forward end of the tunnel, while cushioning shock and lifting the bow; and simultaneously enclosing the transom end of the tunnel with a foil, so as to compress the turbulence and lift the transom.

Abstract: A water vehicle includes a longitudinally elongated hull having a first portion adapted to separate the water by movement of the hull through the water. Foam is generated by the separation of the water. A second portion of the hull is adapted to contain the foam underneath the hull. The vehicle will be supported during propulsion at least in part by a surface of the foam.

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 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 high-speed planing catamaran is comprised of hulls, each of which has a canard planing surface well forward of the catamaran's center of gravity and a main planing surface aft of and closer to the center of gravity. At planing speeds, the canard surface leaves a trough in the water which substantially encloses the hull portion aft of the canard surface. The main planing surface rides on water between the hulls, but outside the trough. The angle of incidence of all surfaces may be adjustable, as may the vertical and lateral positions of each hull's propeller.

Abstract: A marine hull including a plurality of channels extending rearwardly and inclined, in plan, with respect to the central longitudinal vertical plane of the hull, the cross-sectional shape of each channel being curved so that its surface intercepts water when the hull is mobile and that water is caused to leave each channel in a downward direction thereby imparting lift over a major portion of the length of the hull.

Abstract: A surface effect vehicle comprises a hull of a generally rectangular shape concave at the front underside and contouring to a flat planing hull at the stern, an upper surface forming an airfoil, a passenger/operators cabin is mounted on top of the hull and support a ram wing and propulsion system.

Abstract: Streamwise ridges on a lifting wing intercept local flow consisting of free stream and spanwise crossflow to create a pattern of vortices over the wing and aligned with the ridge axes; the vortices act as suction pumps collecting low energy boundary layer fluid, ingesting such fluid into the core of the vortices, transporting it in the streamwise direction, and discharging it into the wake. Fresh fluid from the outer, free stream flow replaces the spent fluid withdrawn by the vortex array. This produces a favorable pressure gradient that maintains laminarity, avoiding the onset of boundary layer transition leading to turbulence. The favorable pressure gradient also suppresses separation on the back side of the wing, where the pressure gradient is normally positive and adverse.

Abstract: An amphibious executive or business airplane, also having military application, possesses sponsons integrated with the airplane fuselage. The trailing end of the sponsons end in a sharp edge, thus eliminating the need for a hull or float step or venting. A channel is formed by the sponsons and the underside of the fuselage, which channel has a constant cross-section and produces a surface lift effect facilitating take-off and landing. A pair of keels beginning substantially aft of the center of gravity of the airplane provide directional stability on the water. The aircraft is preferably jet powered with the inlet of the engines disposed above the sponsons to eliminate water intake. Variable geometry wings of telescoping design maximize aerodynamic performance on take-off and landing and during the high altitude, high speed cruise regime of the flight.

Abstract: A self-propelled waterborne vessel has a generally flat hull undersurface aft of the bow region from which extend side walls (10) and keels (11, 12) defining longitudinally extending channels (8, 9) of which the length approximates to one-third of the length of the vessel. Ducted portions of the channels contain propellers (21) aft of which the ducted portion cross-section is selectively variable by transversely pivoted vanes (18). The attitude of the vessel is controllable by the vanes (18) and by further vanes (36) at the stern. Steering is effected by a propulsive steering unit (25) comprising ducts containing propellers (32) and transversely pivoted vanes (34). Additional ducted propellers (46) can be provided aft and may be retractable into the hull.

Abstract: An improved shallow draft boat useful for coastal fishing or shrimping operations is provided which substantially reduces drag and thus power requirements, and is so maneuverable that the boat can actually be turned completely within its own length without spinning out. The boat includes an elongated hull having an amidships, funnel-shaped motor well along with an axial trough extending from the well to the boat fan-tail; the trough is preferably of decreasing cross-sectional area along its length so that prop wash created by the motor is forced through a progressively smaller volume, thus producing an uplifting force adjacent the boat's stern. Hence, the boat may pass through very shallow water (as little as about eight inches in depth), at full power inasmuch as the boat actually rides upon the motor prop and flattened stern areas of the hull with very little draft.

Abstract: Hydrocraft, capable of maintaining comfortable seaworthy performance at both low and high speeds, in both calm and rough seas, wherein its hull form coordinates high efficiency of at least two zero deadrise planing surfaces with a wave piercing, wedge effect bow segment. The forward portion of the respective concave sides of the bow intersect at the centerline of the hull. The sides of the forward body of the hull rise from the bottom at the chine, vertically then upwardly and outwardly in a concave curvature, the form of which will load the side skin in tension. At a preselected point above the hull bottom, the sharp edged bow is truncated in a conical, forward sloping surface to provide an upward hydrodynamic force to lift the hull over waves which are higher than the gunwale. The parallel after body is located above the after planing surface, and a conical transom closes the stern.

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 stage 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 slightly to port. Water exits from the aft flow chamber with minimum turbulence and cavitation.

Abstract: This invention relates to a boat, the bottom of which is provided with a plurality of downwardly opening channels intended to receive air during the forward movement of the boat in order to produce a reduction of the friction between the water and the bottom surface. In order to make the air inflow into the channels easier these are, regarded from above and from below respectively, extending along their whole extension mainly parallel to the bottom line of the boat in the direction astern from places at the stem of the boat above the water surface to places under the water surface.

Abstract: The specification discloses a modified V-hull for a boat in which an elongate pad forms the lowermost portion of the hull. At positions toward the front of the pad, it has a transverse cross-sectional rounded V-shape across its width, but at the back of the pad, the transverse cross-section is almost flat. The pad has a gradually increasingly acute V-shape in transverse cross-section from the back to the front of the pad, and the pad is linear along linear tracks extending from about the longitudinal center (the keel line) of the elongate pad rearwardly at a track angle with respect to the longitudinal center of the pad. The track angle remains approximately constant from about the back to the front of the pad. Also, the pad is linear at its rear end along an infinity of tracks extending from a point on the pad's longitudinal centerline about three feet from the back of the pad to any point on the back of the pad.

Abstract: A tunnel-type boat-hull construction is operative with substantially reduced frictional resistance in the water and also with improved high-speed stability. An air-withdrawal port is provided in the bow portion of the tunnel, and exit ports which are interconnected to the withdrawal port are provided along generally downwardly facing submerged surfaces of the hull. When the boat hull is operated in a forward direction, air is captured in the forward portion of the tunnel, and a portion of the air is withdrawn through the withdrawal port and is exited through the exit ports. The air which is exited through the exit ports provides lubrication for the submerged hull surfaces so that the hull is operative with substantially improved efficiency; and because the air is withdrawn from the bow portion of the tunnel, the bow uplift effects which are characteristic of conventional tunnel-hull-type vessels when they have been operated under high-speed conditions are substantially reduced.

Abstract: A hull construction for a board useful in water sports, and a board incorporating such a hull, the hull incorporating a pair of air intake chambers extending from the forward end thereof, in the nature of parallel grooves which are mirror images of each other in the axis of symmetry of the hull, to beyond the hull center in the direction of the following end of the hull, a pair of following end grooved vacuum chambers and a strip of ungrooved hull between the ends of the air intake chambers and the vacuum chambers.

Abstract: A planing type boat having a water ballast chamber provided at the bottom of the boat includes a partition wall provided in the water ballast chamber to divide the chamber into front and rear compartments and formed with an opening for communicating these compartments with each other. In the initial stage of planing, the water in the rear compartment is fastly discharged due to a combined action of inertia, gravity and aspiration induced by the outside flow whereas the water in the front compartment which is restricted in its rearward flow by the partition wall structure is discharged relatively slowly as compared with the water in the rear compartment. The weight of the water therefore substantially acts on the front compartment in the initial stage of planing thereby effectively preventing the bow of the boat from being excessively lifted with the result that the time required for entering a complete planing is minimized.

Abstract: A hull or flotation arrangement for an apparatus moving through water is provided with steps forming a plurality of surfaces on which the apparatus rides. The steps are arranged such that the lower edges of a predetermined number of the steps extend deeper into the water than a predetermined number of the lower edges of the remaining steps. The lower points of the steps are arranged so that predetermined numbers of them are deeper than predetermined numbers of others, so that there is a progression extending deeper and deeper into the water. The steps are so constructed that as the apparatus is moved forward, it rises upwardly in the water, causing the steps to rise out of the water progressively as the speed increases, with the hull then riding on only a few steps, thus reducing drag and increasing efficiency.

Abstract: A drag reducing device for barges including a flexible mat carrying a plurality of transversely spaced, elongated flexible tubular air passages open at the top and bottom, suspended from one end of a barge, extending transversely of the barge and adapted to swing longitudinally of the barge as the barge moves longitudinally through a body of water, whereby air from the atmosphere is conducted through the tubular air passages to an area beneath the barge.The drag reducing device is particularly adapted for suspension between the adjacent ends of a pair of barges connected in tandem so that the flexible mat and tubular members swing in a trailing longitudinal direction to direct air beneath the bottom surface of the trailing barge.

Abstract: A bottom exhaust type high speed boat has a hull including a grooved bottom. The engine exhaust pipe extends into a midportion of the grooved bottom. A duct fixed to the surface of the hull extends between the opening of the exhaust pipe and the front of the grooved bottom for transporting exhaust gases to the front of the grooved bottom. The grooved bottom is separated into a forward part and a rearward part, having different depths, by a stepped surface. The exhaust opening is on the rearward part whereas the duct is on the forward part. Gas leakage prevention grooves surround the grooved bottom. A triangular projection having dovetail sides extends from the grooved bottom and the engine propeller is positioned on the projection.

Abstract: A board for aquatic sports is disclosed. The board, during displacement across water, directs a jet or shower of water at the abdominal region of a person lying on the board.

Abstract: An improved barge hull for offshore drilling rigs is disclosed. The invention comprises a channel in the bottom of a barge hull extending from the bottom of said barge hull to the back of said barge hull for directing the flow of water under said barge hull to the back of said barge hull in order to disrupt the relative hydrodynamic stability of a body of water immediately behind said barge hull and thereby decrease the towing resistance of said barge hull.

Abstract: A boat hull incorporating a plurality of pairs of longitudinal planing surfaces symmetrically positioned about the boat keel, and separated by inverted chines extending inwardly of the contour formed by the planing surfaces in providing the shape of the hull.

Abstract: A hull is provided including opposite longitudinal upstanding outer sides and a central depending longitudinal displacement-type keel. The forward ends portions of the outer sides and the keel curve inwardly and upwardly, respectively, and merge to form a forwardly and upwardly tapering bow. The lower portions of the sides, rearward of the bow, terminate downwardly in downwardly and outwardly inclined outer side surfaces of opposite side downwardly and outwardly inclined displacement-type cutwaters whose lower marginal portions are rearwardly and downwardly inclined. The cutwaters include inwardly and upwardly inclined inner side surfaces extending longitudinally thereof and which diverge upwardly away from the corresponding outer side surfaces.

Abstract: A fan-powered water vessel in which an essentially flat-bottomed main hull portion is provided with a central friction reducing, relatively shallow tunnel whereby air forced into the forward portions thereof serves to form an air film between the major parts of the bottom of the boat and the supporting water surface. In addition, a pair of relatively narrow secondary tunnels are provided on either side of the central tunnel and are of a depth substantially greater than that of the central tunnel so as to confine the friction reducing air film between said secondary tunnels. This construction enables the boat to be utilized both on relatively calm inland waters and swamps as well as in choppy waters. An elevated bow provided at the forward section of the main hull divides and spreads waves to further enhance efficiency. The rear of the hull includes a power supply support housing including an air fan.

Abstract: An aquatic recreation vehicle susceptible to use by one or a group of passengers or crew has an integrally formed hull having a plurality of surfaces. The hull is symmetrical about a central vertical symmetry plane which essentially divides the hull longitudinally in half. The surfaces include at least three longitudinally extending sections and at least two longitudinally extending pressure ridges. The pressure ridges are symmetrically located on the bottom of the hull and are inwardly directed toward the vertical symmetry plane. At least two longitudinally extending runners are located on the hull to provide high speed planing lift. The hull surfaces are curved upward at the bow to provide smooth entry into the water. A superstructure is located on the hull and extends longitudinally along a portion of the length of the hull. The combined centers of gravity and buoyancy of the hull and superstructure normally lie essentially in the same vertical symmetry plane.

Abstract: A motorcycle having a body carried on front and rear power-driven wheels in which the wheels are provided with novel tread design cooperating with the body and portions thereof to literally pump water rearwardly while confining it to ridge or crest form centered on the longitudinal centerline of the vehicle whereby to enable the vehicle to travel over water. The body is closed at its top, opposite sides and also at its front and rear ends by front and rear fender wells, respectively, creating an air chamber beneath which the front wheel pumps water to flow rearwardly as aforesaid.

Abstract: A small watercraft including a hull of longitudinally elongated shape having a deck in its upper part, and an engine for thrusting the watercraft forwardly. The hull is formed in the forward and rearward portions of its lower part with water accommodation compartments formed with a plurality of openings for water to flow therethrough into and out of the compartments. When the watercraft is at rest, water flows into the water accommodation compartments through the openings to stabilize the hull. When the watercraft is cruising, the water in the water accommodation compartments is released therefrom through the openings, so that the watercraft lightly cruises.

Abstract: A water walker which is attachable to a user's foot and which, when used in pairs, i.e., one walker for each of a user's feet, allows the user to move across the surface of a body of water while standing upright, includes a buoyant flotation member, a pair of spaced apart runners longitudinally extending along the bottom of the buoyant member, and at least one water control mechanism in the space between the runners. Each control mechanism includes opposed baffles which extend towards one another a distance less than one half the spacing between the runners, and a pivotable gate which is positioned to allow water to pass between the baffles when the walker is moved forward, but which is biased so as to be repositioned to prevent water from passing between the baffles once the walker has completed its forward movement. Each buoyant flotation member includes an overhang portion on the side thereof opposite the adjacent member to enhance the stability of the walker.

Abstract: A motor driven hydroplaning boat has a hull of symmetrical generally smooth surfaced configuration which converges towards an apex at a bow thereof and widens amidships to form a pair of laterally and downwardly extending wings. A forward bottom portion of the hull, from the bow to beneath the wings, forms a generally smooth surfaced concave downward tunnel. The wings smoothly narrow aft of amidships and become generally horizontal from amidships aft. A top of the hull is of a generally smooth minimal air resistance shape. A fore foil structure is mounted to extend downwardly from the fore tunnel. An aft foil structure is mounted to extend downwardly from an aft bottom portion of the hull. The overall boat has low air resistance yet overall high stability and can be turned relatively sharply.

Abstract: A boat hull having a bow and stern and requiring relatively small draft, having low frictional drag characteristics for high speed, stable performance, wherein the hull has a scooped configuration and defines a tri-keel design, wherein the side and bottom walls, making up the hull, define a first, open scoop portion and a second primary keel portion. The open scoop protion is of concave, curvilinear configuration and extends to a point rearwardly of the mid-point of the hull where it merges into the second or primary keel portion. The bottom and side walls of primary keel portion are V-shaped in configuration to thereby define the primary keel which extends from the merging surface to the stern. The first and second portions also cooperatively define about co-extensively therewith, extending from the open scoop portion, a pair of spaced apart secondary keels which extend from the approximate box of the hull to the stern thereof.

Abstract: A water ski particularly adapted to function as the front ski of a twin ski, jet-driven water vehicle which is steered by turning of the front ski. Sections of the water ski define a planing surface and a pair of inclined, laterally spaced side surfaces extending downwardly and laterally of the planing surface. The portions of the side surfaces lying in or cut by a horizontal plane are equidistant from each other when the planing surface is upwardly tipped at a predetermined angle. At this angle the pair of juncture lines formed between the pair of inner surfaces and the planing surface are laterally divergent in a downstream direction when viewed from above. Reduced frontal drag results.

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.