Abstract: The present invention is concerned with a vessel training device which comprises a sleeve adapted to be reversibly mounted and self retaining about the hull of a rowing boat or the like, and carrying one or more floats via a boom mounted to the sleeve.

Abstract: As typically embodied, the present invention's add-on device includes two wedge-shaped structural components that are oppositely congruent and symmetrically connected. In profile, the device describes a pair of nearly triangular quadrilateral figures that are enantiomorphs (mirror images) with respect to the linear bisector (mirror line) at which they join. The device's V-angular upper surface defines the same V-angularity (“deadrise”) as does a V-angular hull bottom, the device thus fitting beneath the hull bottom. The device's V-angular lower surface defines a different angularity, which is imparted to the hull bottom when the device is attached thereto. According to typical inventive practice, the device alters the hull bottom's V-angularity by at least 1° and, at least, covers approximately 100% of the hull bottom's widthwise expanse along approximately 50% or more of the hull bottom's lengthwise expanse.

Abstract: A watercraft has a hull having a bow, a deck disposed on the hull, an engine connected to the hull, a propulsion system operatively connected to the engine, a first bow sponson disposed on a starboard side of the bow, and a second bow sponson disposed on a port side of the bow. A sponson suitable for use on a bow of a watercraft is also disclosed.

Abstract: The present invention generally provides mold modules for constructing boat hulls, methods of constructing boat hulls using the mold modules, and hulls constructed using the mold modules. The modules may be adjustable, and may be included in a kit for building the hull of many boats of different dimensions but generally the same shape. Each mold module generally comprises a mold in a shape complementary to that of a portion of a boat hull, and an edge mold to form the edge of the hull part formed by that mold module. A mold module according to the present invention may also comprise one or more mold adjustment areas, and calibrators for selecting the boat hull dimensions. Methods for using the aforementioned mold modules generally comprise steps of molding hull parts, removing them from the mold modules, aligning them and finally attaching them together.

Abstract: A shallow draft boat having a boat hull that allows for stability, maneuverability, and speed while needing only inches of draft. The hull generally includes a ski, a bottom shell, a left and right chine and a bow wrapper.

Abstract: An apparatus comprises a structure having a first side, a second side substantially opposite to the first side, a flexible skin, and a plurality of deformable assemblies. The flexible skin is attached to the first side and the second side of the structure. The plurality of deformable assemblies is moveably connected to the structure, in which each deformable assembly in the plurality of deformable assemblies has a vertex and a base. The each deformable assembly in the plurality of deformable assemblies has a height that is capable of changing to change a shape of the structure and a shape of the flexible skin.

Abstract: A boat body for a boat includes a projecting portion arranged to support one or more outboard motors at a position spaced upward and rearward from a transom. The projecting portion extends from a rear portion of the transom of the boat body, and the projecting portion supports the outboard motors at locations upward and further rearward than in a case where the outboard motors are directly installed on the transom. The projecting portion includes a projecting member that is bilaterally symmetrical and that decreases in width in a rearward direction and in an upward direction. The projecting portion includes a side thruster passing through the projecting portion in a horizontal direction. When viewed from the side, a lower edge portion of the projecting portion includes a slanting portion that is generally linear and that extends rearward and upward from a lower portion of the transom. When viewed from the rear, the lower edge portion of the projecting portion has a generally V-shape.

Abstract: An improved stern design for many types of small watercraft to eliminate “tail dragging”, porpoising, oversteer and “slide out”, improve longitudinal tracking, and provide faster planing at lower speeds. This hull extension, consisting of two buoyant sponsons extending astern of the motor output, supports the weight of the entire motor propulsion unit, extends the planing surface, shifts the center of buoyancy rearward, resulting in an ability to maintain an even fore-aft keel in a very lightweight hull. Under acceleration and cruising, high pressure under the extensions along with an improved center of gravity keeps the boat from tail dragging. Interior chines formed as part of the inner lower surface of the sponsons provide straight tracking under power, even without other hydrodynamic aids, and provide resistance to oversteer or “slideout” in turns. The long sponson extensions protect an outdrive system from contact at the stern or sides of the boat.

Abstract: The invention relates to an aerodynamic wing in the shape of a tubed perfect square, the vertical stabilizers and air brake being built into the structure thereof, characterized in that said wing reduces induced drag and increases the efficiency of aircraft in flight.

Abstract: A hull structure has a chine serving as a boundary between a broadside and a bottom of a hull. The hull has a configuration in which the hull has a maximum depth in a vicinity of a central position of the hull, the chine is provided so that its level position becomes gradually lower from a bow side toward a stern side, and the bottom has a cross-section having a substantially V-shape from the bow toward the stern, the V-shape having an inner angle becoming gradually smaller within a range of from about 80° to 100° from the bow toward a central portion of the hull and becoming gradually larger from the central portion thereof toward the stern.

Abstract: Compound hull for electric-powered, cruiser-type vessels having a unique hard chine displacement wave form hull that recycles wave energy to minimize drag and results in lowered power requirements for long-period cruising at displacement hull speeds. The inventive hull comprises: 1) an upper hull portion having a flat bottom square transom, the bottom curve of the hull sides of which match the vessel's wave form at hull speed, mated to, 2) a bottom hull portion formed as a double ended V-bottom lower displacement hull having a constant varying dead-rise. The inventive hull requires up to 50% less power than conventional cruisers of other hull shapes, at displacement hull speed.

Abstract: A hull (1) for a marine vessel (10) comprising an elongate body (2) that tapers outwardly from a foremost location, the bow (3), and tapers inwardly toward the aft (4) such that the aft (4) of the body (2) is significantly reduced in profile with respect to a point in the hull at which the inward taper commences.

Abstract: The invention relates to two parallel added floaters (2) for watercraft, which are fixed to the stern (1a) on a watercraft hull (1) or a platform element (31) whereby the single auxiliary bottom (5) is positioned higher or for the most part positioned higher than the hull bottom (6) and forms a step. The added floaters (2) create on the one hand a static lift (As) and on the other hand a dynamic (Ad) lift.

Abstract: A powerboat with a rooster tail depressor (RTD) includes a hull, a propulsion subassembly on the hull, and a rooster-tail-suppressing subassembly on the hull. The propulsion subassembly propels the hull forwardly, producing a propulsion discharge that extends rearwardly of the stern. The rooster-tail-suppressing subassembly extends rearwardly of the stern over at least a portion of the propulsion discharge where it functions to suppress the formation of a powerboat rooster tail (e.g., for radar signature reduction and increased propulsion efficiency).

Abstract: A marine vehicle includes a hull, a rudder, a propeller, a swirl generator mounting region provided on an outer surface of the hull and located on a port side or a starboard side where a rotation direction of the propeller is downward, and a pre-swirl generator having a swirl creating wedge disposed in the swirl generator mounting region. The swirl generator mounting region is disposed in front of a central axis of the rudder and behind a vertical line spaced from the central axis by a distance that is 0.2 times the length of the vehicle. The swirl creating wedge is inclined with respect to a waterline by an angle (?1) of 13°-45°. The pre-swirl generator can produce a flow guiding effect that enhances propulsive efficiency of the marine vehicle.

Abstract: A marine vehicle includes a hull, a rudder, a propeller, a swirl generator mounting region provided on an outer surface of the hull and located on a port side or a starboard side where a rotation direction of the propeller is downward, and a pre-swirl generator having a swirl creating wedge disposed in the swirl generator mounting region. The swirl generator mounting region is disposed in front of a central axis of the rudder and behind a vertical line spaced from the central axis by a distance that is 0.2 times the length of the vehicle. The swirl creating wedge is inclined with respect to a waterline by an angle (?1) of 13°-45°. The pre-swirl generator can produce a flow guiding effect that enhances propulsive efficiency of the marine vehicle.

Abstract: A high performance planing hull, designed in particular for boats with drives of fixed or non-steerable type. The hull comprises an additional volume, which is integrated in the immersed part of the stern of the hull. The additional volume extends substantially in longitudinal direction and is symmetrical with respect to the longitudinal plane of symmetry of the hull.

Abstract: A multi-purpose expedition vessel having a aluminum alloy hull, where the aluminum alloy hull can have a aluminum alloy hull bottom with a deadrise bow elevated above a waterline, an aft portion comprising a stern, a port side, a starboard side, a central axis between the starboard and port sides. The aluminum alloy hull of the vessel can have a first plurality of lifting stakes secured to the port side of the deadrise bow, and a second plurality of lifting stakes secured to the starboard side of the deadrise bow. The aluminum alloy hull can have at least a first level disposed within the aluminum alloy hull, and the aluminum alloy hull can have a superstructure disposed on it having various structures, such as a stateroom, a steering station, or a floatation roof.

Abstract: A ship and associated methods of operation. In an example embodiment, a method of transporting includes providing multiple vessels each having a hull defining an air cavity over a water surface. Different ones of the vessels are loaded with material destined for different end locations. The vessels are connected to one another with rigid couplings to effect tandem movement of the multiple vessels over water as one ship while permitting each vessel to undergo changes in pitch. The vessels are transported to a first destination and one or more of the vessels are disconnected from the ship.

Abstract: A drag reduction mean which consists a duct and a support mean which duct can reflect passed through flows and which is mounted on one end of the support mean which another end can be mounted on an object which can move in a fluid; the length of the support mean being able to be altered by a mechanical mean; the ratio of the cross-sectional areas of the entrance and the exit of the duct being able to be altered; the normal directions of the exit of the duct being able to be altered; the algorithms of using the drag reduction means being revealed.

Abstract: The variable trim boat comprises a pair of hollow bodies, arranged on the sides of the boat in symmetrical position with respect to the longitudinal axis, which stretch from a central position of the hull up to the stem area. The hollow bodies comprise respective no-leakage-chamber box structures, isolated from the boat, suitable to be kept empty or filled up with water to improve the trim and the stability of the boat both in static and in dynamic conditions.

Abstract: A boat stabilizer that is attachable to the anti-cavitation plate or other structure of the lower drive unit of a boat motor without permanently modifying the structure of the anti-cavitation plate or other structure is provided. The shape and size of the boat stabilizer causes the stabilizer to effectively harness and control the thrust energy generated by the propeller resulting in improved thrust and fuel efficiency. Due to various features, the drag associated with the boat stabilizer is kept to a minimum. Finally, decals and other decorative elements are integrally embedded into the top surface of the inventive boat stabilizer using in-mold decoration (“IMD”) technology which makes the elements resistant to ultra-violet light, virtually indestructible and highly appealing. A boat motor, a method of attaching a boat stabilizer to a boat motor and a method of molding a boat stabilizer having at least one decorative element integrally embedded in the top surface thereof are also provided.

Abstract: A versatile watercraft of the present invention comprises a base wing, a C-wing, and preferably a plurality of vertical stabilization knives. The base wing extends horizontally from the right side of the watercraft to the left side of the watercraft, and longitudinally, for at least a third of the length of the watercraft. The C-wing, extends above the base wing. The C-wing is comprised of at least two essentially vertical walls and an essentially horizontal top. The watercraft also comprises at least one propulsion device. In the preferred embodiments, a plurality of vertical stabilization knives extends vertically below the base wing and extends longitudinally for at least a third of the length of the watercraft.

Abstract: A vessel hull having a pair of vents formed in the chine on each side for allowing air to be introduced to the bottom and a pair of downwardly extending fins formed longitudinally along the chine adjacent to each vent. Each vent can be formed by a recess in the chine dividing the chine into a forward portion and an aft portion. Each fin is preferably formed longitudinally along the aft portion of the chine and extends below the waterline. The fins counterbalance the removal of a portion of the chine to vent the bottom and increase stability during turns. The hull preferably also includes a pair of chine extensions projecting aft of the transom on each side for reducing or eliminating side-to-side oscillation of the stern when the hull is propelled through the water at slow speeds.

Abstract: A rudder and dynamic trim adjusting apparatus for a boat includes a rudder, a rudder shaft extending from the rudder and being rotatable about a longitudinal axis thereof to rotate the rudder, trim fins extending from the rudder, along at least one transverse axis transverse to the longitudinal axis, and a mechanism connected to the trim fins, and being operable, independently of rotation of the rudder shaft to rotate the trim fins about the at least one transverse axis. Methods of controlling an attitude of a boat hull are provided.

Abstract: A hull structure has a chine serving as a boundary between a broadside and a bottom of a hull. The hull has a configuration in which the hull has a maximum depth in a vicinity of a central position of the hull, the chine is provided so that its level position becomes gradually lower from a bow side toward a stern side, and the bottom has a cross-section having a substantially V-shape from the bow toward the stern, the V-shape having an inner angle becoming gradually smaller within a range of from about 80° to 100° from the bow toward a central portion of the hull and becoming gradually larger from the central portion thereof toward the stern.

Abstract: A ship designed for use at high speed and heavy seas having a single long and slender hull with a narrow beam and a more or less vertical bow, whereby the front half of the hull has more or less vertical sides, minimal flare in the bow sections and towards the bow an increase in draught at its center line combined with a more or less similar increase of freeboard and whereby the aft end of the hull has a flat or slightly V-shaped bottom with one or more propellers and/or waterjets as propulsion means. In accordance with the invention the bow has a fillet radius of at least 1% of the beam.

Abstract: The boat hull includes a bow, a stern and a bottom surface which extends from the bow to the stern. The hull includes a bottom surface with a deep-V shaped portion extending from the bow to a hull point which is aft of the mid-point of the bottom surface, approximately two-thirds thereof. At least two steps, referred to as flat steps, are included in the bottom surface of the boat, between the hull point and the stern. The steps extend across a portion of the bottom surface. Flat pads extend from each step to the next step or to the rear of the stern. A decrease in the size of the entire hull, referred to as a hull step, occurs at the second or third step in the bottom surface of the boat.

Abstract: A twin-hull catamaran boat or vessel comprising of four hydrodynamic pod sections connected with a mid-span recess on each hull that receives mechanically inducted gas or air for hull support. Each hull shape of the twin-hull catamaran configuration contains one V-shaped hull portion forward (bow), one mid-length hull cavity portion that receives pressurized gas or air therein (amidships), and one V-shaped hull portion aft (stern). The V-shaped bow portion creates hydrodynamic lift, the air or gas mechanically pressurized mid-length recess portion creates an air cushion to lift the hull in order to reduce wetted surface and drag on the hulls, and the V-shaped stern portion provides hydrodynamic lift to support the aft portion of the twin-hull catamaran configuration and also to provide an aft sealing body for the mechanically pressurized air or gas mid-length cavity.

Abstract: A hybrid boat hull. In a first embodiment, the hybrid boat hull comprises a first and second outer elongated hulls each curved inwards to respectively define first and second keel fins which provide buoyancy and act as inclined hydrofoils when the hybrid hull is run at high speed. In a second embodiment, the hybrid boat hull further comprises an elongated central hull, which serves to dampen the effect of slamming of waves on the underside of the hybrid boat hull.

Abstract: A multi-mission/purpose ground-effect craft is provided which is derived from a common modular platform which includes a hull; an inner floor structure adapted to be installed over the hull; a body adapted to be attached to at least one of the top surface of the hull and the inner floor structure, such that a interior compartment is formed thereinside; a tail wing assembly adapted to be attached to the aft end of the body; a forward nose cowl adapted to be attached to at least one of the forward nose portion of the hull and the forward body portion of the body; a windshield integrated into the forward end of the body; at least one door assembly integrated into the left or right body side; at least one window assembly integrated into the left or right body side; a propulsion system integrated within the aft end of the body; and a retractable skirt attached and draped from the outer or inner perimeter of the hull.

Abstract: An anti-cavitation plate actuating system incorporates pressurized air selectively applied through a control valve to an air assist cylinder. The cylinder, when pressurized, applies force to anti-cavitation plate return springs; the force is not sufficient to expand or retract the springs but merely to apply a pre-load. A control pedal operating through a control shaft applies additional force through an actuating shaft connected through a control lever to the anti-cavitation plate to lower the plate.

Abstract: The present invention relates to an improved amphibious craft or vehicle and, in particular, but not exclusively, to a craft or vehicle that may be used for commercial and rescue tasks in a great variety of weather conditions. To achieve this, an amphibious vehicle comprises a fixed geometry planing hull (2) and a skirt system (4). This has as an advantage that the fixed geometry planing hull (2) allows the craft or vehicle to operate in high waves, strong winds or other adverse conditions too severe for known hovercraft of a similar size, while the skirt system (4) contains a cushion of air providing the craft or vehicle with a full amphibious capability so that the craft can operate as a conventional hovercraft in good conditions or enter and leave water in any conditions.

Abstract: A control surface system for a marine vehicle is provided. The control surface system includes a control member having at least two control portions fixedly connected at a predetermined spacing from each other. The control portions each have opposed surfaces, with the control portions being rotatable about an axis.

Abstract: A Fluidynamic Lift Combined Array, Technology for flying, and/or land, and/or other motor vehicles comprises: a. an aerodynamic structure of chord-telescopic smooth-united multisegment lifting wings; and/or b. a set of hydrodynamic circuits including closed loop waved tunnels each with placed inside pump impelling operative liquid and having curved elbows with lifting winglets; and c. a method of generating high lift forces in combined fluidynamic, self-boosting, accumulative, and energy integrating and conservative technology. This proposal can provide: Short, safe, convenient for people, and appropriate for planes takeoffs and landings at speeds about 20 miles per hour. Sure overcoming any difficulties connected with heavy load for land and other vehicles. High general efficiency and profound reliability in upkeeping and thrifty technology with substantial energy conservation by additional lift generated in any tense situations.

Abstract: Boat hulls or assemblies have sequences of groups of downward-facing sections such as planing sections. A sequence includes a lowermost group and supplemental groups above it. Each group could, for example, be a pair, and the pairs could be port-starboard symmetrical. The lower surface is shaped so that the boat hull, in a series of speed ranges, planes on successively lower groups, planing on the lowermost group in the highest range. The trim angle can be between 3.0° and 6.0° in a speed range. The boat hull can be structured so that, when planing on one of the groups, the next higher group dries out. For example, each pair of sections can have an outward angle not smaller than the next inward pair's. The lowermost group can have a maximum width approximately equal to an ideal beam width for a set of displacement characteristics and its target maximum speed.

Abstract: A vessel hull having a pair of vents formed in the chine on each side for allowing air to be introduced to the bottom and a pair of downwardly extending fins formed longitudinally along the chine adjacent to each vent. Each vent can be formed by a recess in the chine dividing the chine into a forward portion and an aft portion. Each fin is preferably formed longitudinally along the aft portion of the chine and extends below the waterline. The fins counterbalance the removal of a portion of the chine to vent the bottom and increase stability during turns. The hull preferably also includes a pair of chine extensions projecting aft of the transom on each side for reducing or eliminating side-to-side oscillation of the stern when the hull is propelled through the water at slow speeds.

Abstract: The application relates to water craft hulls having improved hydrodynamic stability. A hull (1) is claimed in which the center of gravity (Cg) is substantially vertically aligned with the center of hydrodynamic lift (Cp) of a lifting surface of the hull, both at lift-off speed and at design speed, and preferably also at speeds below lift-off, and at all speeds between lift-off and design speed and above. A hull having a relatively high aspect ratio at design speed, and preferably also at lift-off speed, is also claimed. In the preferred embodiment, the hull is generally delta-shaped in plan view.

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

Abstract: An improved boat or ship with a combination planing and displacement hull, fins mounted near the aft section provide increased planing area while still permitting a tapered aft of favorable prismatic ratio for when the boat or ship is in the displacement mode.

Abstract: A stern flap has a “contour” shape which facilitates installation thereof upon the curved stern of a ship. The stem flap's lower surface includes an intermediate region and two curvedly tapered end regions. The intermediate region is delineated forwardly by a curved leading edge and aftly by a parallelly curved trailing edge, the chord length therebetween being constant. The curve characterizing the flap's leading edge is congruent with the curve characterizing the ship stern's lower transverse edge (the junction between the ship's bottom and the ship's stern), thereby permitting contiguous disposition of the flap's leading edge relative to the ship's lower transverse edge, as well as permitting even and unbroken disposition of the flap's lower surface relative to the ship's bottom.

Abstract: The invention of a sailboat that uses three ways of creating lift on the hull of a boat so that it rides higher on the water and gives the sailors a fast dry ride.

Abstract: A new form of water plane interface device for maritime base ground effect craft that minimizes power requirements, automates wave action response, and controls flight attitude and altitude. A ground effect craft requiring no active aeronautical control surfaces, thus radically simplifying operation. Mounted to a high performance blended-wing lifting-body, having retractable, variable geometry, and graduated surface plane appendages which are shock dampened to enhance passenger comfort (FIG. 1; 13,15,16). Forward appendages (FIG. 1; 13) are independently operable and provide for coordinated bank turns, and powered lift assist during transition from water-to-air born operation. Aftermost appendage (FIG. 2,16) replaces conventional high drag horizontal tail surfaces and provides anti-blow over characteristics (FIG. 2;8). Utilizes conventional race boat type propulsion systems and rudder control (FIG. 26,7).

Abstract: Presented is an improved Surface Effect Ship (SES) that offers the high efficiencies of the pressurized air cushion supported generic flexible bow and stern seal SES but without the generic SES's shortcomings that are due largely to its 80 percent total hull width flexible bow and stern seals. This is accomplished in the instant invention by use of forward extending rigid bow members positioned both sides of a pressurized hull supporting gas cushion where the width of the sidehulls make up a majority of the width of the instant invention improved surface effect ship with the remainder, less than 35 percent of vessel width normally, made up by a gas cushion forward seal member disposed between the bow members. Gas cushions may extend forward into undersides of the sidehull bow members to further reduce wetted area resistance. Longitudinally oriented fluid fences may be incorporated to at least partially separate portions of the gas cushion and thereby dampen pressure perturbations in the gas cushion(s).

Abstract: The present invention over-comes the prior art deficiencies by, in part, defining a hull bottom that decreases the total resistance and thereby reduces the propulsion power needed to propel a boat of a certain weight to a given speed. The invention separates the functions of the planing process resulting in a hull with staged longitudinal steps wherein each step consists of a fully defined hull underbody with a chine and bow and stern. Each intermediate chine describes a supplemental planing surface which is designed to lift the hull dynamically and to position the hull on the next narrower step that supports the weight of the boat and creates the forces needed to further lift the hull to the next narrower chine in two or more stages depending upon the size and weight of the boat to lift the hull to the central planing surface to achieve the desired top speed. The hull for each step is described by its chine, hull bottom, deadrise angle, bow and stern dimensions optimized to the “ideal beam”(Ref.

Abstract: Presented is an improved Surface Effect Ship (SES) that offers the high efficiencies of the pressurized air cushion supported generic flexible bow and stern seal SES but without the generic SES's shortcomings that are due largely to its 80 percent total hull width flexible bow and stern seals. This is accomplished in the instant invention by use of forward extending rigid bow members positioned both sides of a pressurized hull supporting gas cushion where the width of the sidehulls make up a majority of the width of the instant invention improved surface effect ship with the remainder, less than 35 percent of vessel width normally, made up by a gas cushion forward seal member disposed between the bow members. Gas cushions may extend forward into undersides of the sidehull bow members to further reduce wetted area resistance. Longitudinally oriented fluid fences may be incorporated to at least partially separate portions of the gas cushion and thereby dampen pressure perturbations in the gas cushion(s).

Abstract: Presented is an advanced Surface Effect Ship (SES) that offers the high efficiencies of the pressurized air cushion supported generic flexible bow and stem seal SES but without the generic SES's shortcomings that are due largely to its generally about 80 percent total hull width flexible bow and stem seals. This is accomplished in the instant invention by use of forward extending rigid bow members positioned both sides of a pressurized hull supporting gas cushion such that the width of the sidehulls make up a majority of the width of the instant invention advanced surface effect ship with the remainder, normally less than 35 percent of vessel width, made up by a gas cushion forward seal member disposed between the bow members. Gas cushions may extend forward into undersides of the sidehull bow members to further reduce wetted area resistance.

Abstract: Presented is an enhanced Surface Effect Ship (SES) that offers the high efficiencies of the pressurized air cushion supported generic flexible bow and stern seal SES but without the generic SES's shortcomings that are due largely to its 80 percent total hull width flexible bow and stem seals. This is accomplished in the instant invention by use of forward extending rigid bow members positioned both sides of a pressurized hull supporting gas cushion where the width of the sidehulls make up a majority of the width of the instant invention enhanced surface effect ship with the remainder, less than 35 percent of vessel width normally, made up by a moveable seal member disposed between the bow members. Gas cushions may extend forward into undersides of the bow members to further reduce wetted area resistance. Longitudinally oriented fluid fences may be incorporated to at least partially separate portions of the gas cushion and thereby dampen pressure perturbations in the gas cushion(s).

Abstract: A hull form which operates in the speed ranges where both planing and wave making affect hull resistance is presented with a configuration which reduces wave drag and improves performance in very fast and ultra-faste speed ranges. The specific distribution of immersed cross-sectional area minimizes bow wave making and optimizes the closing wake. Bow wave impedes forward motion of a hull form. Stern closing wake pushes the hull forward and enhances the forward motion. The bow sections are designed so that they have a “hollow” entrance configuration which decreases the effort to spread the water and in turn diminishes the wave making as the hull pushes through the water. The stern sections are designed to be of such a configuration that as the water spread by the bow (34) now must close in around the stern (35) of the hull, the wave height is increased so that the closing wake exerts a forward thrust on the hull.

Abstract: An unventilated, stepped hydroplaning boat hull has at least one midship step. Two separated wetted planing surfaces are thereby established—a forward surface just forward of the step and an aft surface just forward of an aft edge of the hull. The angles of attack of each planing surface preferably lie in the range 2.0-6.5 degrees, and are preferably equal. The midship step is preferably located longitudinally in a range of 0.45 to 0.51 times the projected chine length of the hull, measured aftward from a forwardmost point of the chine.