Abstract: A pontoon boat is provided that includes a deck and a plurality of pontoons running longitudinally beneath the deck and providing buoyancy to the pontoon boat. The plurality of pontoons include a multi-chine configuration that increases the stability of the pontoon boat and provides handling characteristics similar to that of a hulled boat. The plurality of pontoons may include two outer pontoons and a third pontoon positioned laterally intermediate the outer pontoons. The third pontoon may include a plurality of chines, and each of the outer pontoons may include at least one chine. At least a portion of each of the at least one chines of the outer pontoons may be positioned vertically below the plurality of chines of the third pontoon. The chines on the third pontoon may extend longitudinally further than each of the at least one chines of the outer pontoons.

Abstract: A marine monitoring and debris collection scow is provided, the scow comprising: a hull which includes an open stern, a bow opposite the open stern, a deck extending between the open stern and the bow and forming a bottom on an underside, the bottom extending between the open stern and the bow; a frame, the frame which is attached to the deck, the frame including a front, a back which is opposite the front and sides extending between the front and the back; at least one flotation chamber which extends around the sides and the front of the frame and forms a gunwale; a housing mounted on the deck; and a microcontroller unit housed in the housing, the microcontroller unit configured to receive a data set from at least one sensor, to store the data set, to process the data set into a processed data set and to send the processed data set to a radio.

Abstract: The invention provides a suspended catamaran target boat, including a deck, a suspension structure and two buoyancy units, the suspension structure is connected to upper sides of the two buoyancy units, and the deck is mounted on the suspension structure; the suspension structure includes at least two suspension assemblies including an upper base, a lower base and two support rods. The support rods are hinged between the upper base and the lower base, and the upper base, the lower base and the two support rods form a four-bar linkage mechanism, where a shock absorber and a restricting mechanism are installed between the upper base and the lower base. The deck is provided with a main controller, an acceleration sensor and a heel sensor, and the main controller is respectively electrically connected with the acceleration sensor, the heel sensor and each of the restricting mechanisms of the two suspension assemblies.

Abstract: A ground effect craft having a ground effect wing, a plurality of sponsons, and a control system is disclosed. The ground effect wing may include a fore ground effect wing and an aft ground effect wing. The ground effect wing may generate a stabilizing moment on at least one sponson to stabilize the ground effect craft. The plurality of sponsons may be dynamically coupled to the body. The plurality of sponsons may be dynamically coupled to each other. The dynamic coupling may permit the sponsons to move relatively independent of the body and each other, thereby stabilizing the ground effect craft. The ground effect craft may include a stabilizing wing.

Abstract: The present invention concerns a landing gear (1) for a light aircraft, i.e. weighing less than 5.7 tonnes, the landing gear consisting of at least one wheel (3) attached to a chassis or to a fuselage of the aircraft by means of a connecting element (2). According to the invention, the wheel (3) is connected to the connecting element (2) via a system (4) of two damping cylinders arranged between the wheel (3) and the connecting element (2).

Abstract: A catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames are spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames extends upwardly in an inverted u-shape, providing a space under the frame and in between the barges that enables a marine vessel to be positioned in between the barges and under the frames.

Abstract: A ground effect craft having a ground effect wing, a plurality of sponsons, and a control system is disclosed. The ground effect wing may include a fore ground effect wing and an aft ground effect wing. The ground effect wing may generate a stabilizing moment on at least one sponson to stabilize the ground effect craft. The plurality of sponsons may be dynamically coupled to the body. The plurality of sponsons may be dynamically coupled to each other. The dynamic coupling may permit the sponsons to move relatively independent of the body and each other, thereby stabilizing the ground effect craft. The ground effect craft may include a stabilizing wing.

Abstract: The invention relates to boat building and can be used in the building and modification of sea-going high-speed keeled monohull sailboats or sail and motor boats with a high sail power to weight ratio, where a single, narrow, wave-penetrating displacement hull is used. To provide for the stable controlled movement of a keeled monohull sailboat or sail and motor boat in wave penetration mode, i.e.

Abstract: A catamaran lifting apparatus is disclosed for lifting objects in a marine environment. The apparatus includes first and second vessels that are spaced apart during use. A first frame spans between the vessels. A second frame spans between the vessels. The frames are spaced apart and connected to the vessels in a configuration that spaces the vessels apart. The first frame connects to the first vessel with a universal joint and to the second vessel with a hinged connection. The second frame connects to the second vessel with a universal joint and to the first vessel with a hinged or pinned connection. Each of the frames provides a space under the frame and in between the barges that enables a package to be lifted and/or a marine vessel to be positioned in between the barges and under the frames. In this fashion, an object that has been salvaged from the seabed can be placed upon the marine vessel that is positioned in between the barges and under the frames.

Abstract: A propulsion assembly utilizes at least one fluid propulsion chamber operationally attached or mounted to a vessel. Each fluid propulsion chamber generally comprises an outer housing and an inner sleeve; the outer housing is slidably disposed relative to the inner sleeve. Each inner sleeve further includes at least one water intake vent or aperture, and at least one outlet nozzle or jet. Pedal assemblies are moveably mounted within elongated slots or apertures extending through the vessel. A linkage assembly operationally connects the pedals to the at least one fluid propulsion chamber. Force imparted on said pedals (such as by the legs/feet of a user) is transferred to the fluid propulsion chambers by said linkage assembly to generate positive thrust to propel the vessel.

Abstract: A watercraft includes a hull having inner and outer surfaces and at least one collapsible strake coupled to the hull. The collapsible strake includes a movable skin hingedly coupled to the hull. The collapsible strake also includes a dampening element and a negative stiffness element each extending from an inner surface of the movable skin to the outer surface of the hull. The movable skin is configured to rotate between an uncollapsed configuration having a first stiffness and a collapsed configuration having a second stiffness greater than the first stiffness.

Abstract: A watercraft has a deck; central, left and right pods connected to a bottom of the deck; and a helm assembly disposed on the deck. The central pod is laterally centered relative to the deck. The central pod has a central hull defining a central tunnel, a motor connected to and disposed at least in part in the central hull, and a jet propulsion system disposed at least in part in the tunnel and operatively connected to the motor. The left pod is disposed at a left of the central pod and is laterally spaced from the central pod. The left pod has a left hull that is narrower than the central hull. The right pod is disposed at a right of the central pod and is laterally spaced from the central pod. The right pod has a right hull that is narrower than the central hull.

Abstract: A sailboat is described having a boat hull (1), two flow profiles (2, 3) protruding laterally from the boat hull (1), and at least one underwater hydrofoil (16). To be able to achieve high travel velocities while maintaining the stability of the sailboat and balanced control behavior, it is proposed that the flow profiles (2, 3) protrude outward in a V shape from the boat hull and each have an aerodynamic stabilizer forming an aerodynamic aileron (4, 5), and/or the at least one underwater hydrofoil (16) is provided with a hydrodynamic stabilizer forming a hydrodynamic aileron.

Abstract: A boat comprises a deck supported by one or more deck floats, and a paddle wheel cockpit comprising a seat proximal to a pedal-driven paddle wheel adapted to engage water and propel the boat; wherein the deck and the paddle wheel cockpit are joined by at least one cockpit hinge that allows the paddle wheel cockpit to fold over the deck, in some embodiments.

Abstract: A standup paddleboard outrigger includes a long, narrow, lightweight displacement hull and a pair of outrigger pontoons mounted to a bridge. The two parts disengage for easy storage and transport. The hull has a platform to stand on. Paddling with a long handled paddle propels the craft through the water. The outriggers provide lateral stability/support and actuate the rudder in order to make turns. When a person stands on the platform and shifts body weight, the rudder will rotate to the right and the craft will turn to the right. The more weight that is shifted, the greater the turning action. The responsiveness to the shift of body weight can be adjustable for personal preference either firmer or more flexible, as is the turning response of the rudder fine or coarse turning.

Abstract: A pressurized air cushioned hull with fixed rigid side, front and rear seals. The hull includes a plurality of keels, with an air cushion disposed between inboard walls of each keel and an air cushion created/disposed along the outboard walls of each keel. These air cushions along the outboard walls of the keels are created by angling each keel by about 0.02° to about 1° relative to the longitudinal axis of the hull, wherein the left keel(s) is rotated clockwise and the right keel(s) is rotated counterclockwise, such that a distance between the keels is smaller at the front end of the keels than at the rear end of the keels. This slight angle was found to allow air, rather than water, to contact the outboard walls, unexpectedly reducing drag resistance a significant amount, thus improving performance of the hull as a whole.

Abstract: Embodiments described herein provide a collapsible high-performance multi-hulled watercraft which may be easily assembled/disassembled and comprised of a plurality of symmetrically shaped planar hulls which are laterally spaced and provide a shallow water draft; a deck platform releasably attached and overlying the plurality of symmetrically shaped planar hulls having at least one seat, marine radar, translucent protective shield and skid plate; and at least one propulsion unit which may releasably attached to the platform and which extends below the water line to enable high performance stability and maneuverability to the vessel.

Abstract: The present invention relates to a vessel having a superstructure that is movable to increase and/or reduce space in one of at least two zones on the deck of the vessel. The invention further relates to an amphibious vehicle having motive pods that move in an athwartship direction and then downwardly when the motive pods are deployed. The invention further provides for a ramp arrangement for a vessel that allows for an increased amount of deck space, and facilitates ingress and/or egress from the vessel by cargo or passengers.

Abstract: A pontoon boat includes at least two pontoon tubes, a platform supported on the at least two pontoon tubes, and an occupancy compartment capable of containing at least one occupant, the occupancy compartment having a length, a width, an upper portion extending vertically above the platform that includes a ceiling, and a lower portion extending vertically below the platform and into one of the at least two pontoon tubes, the lower portion including a floor surface for supporting the occupant. An entrance to the occupancy compartment is provided in the upper portion that permits the occupant to enter and exit the occupancy compartment.

Abstract: Boats can be adapted to generate a wake that is well-suited for the sport of wake surfing. For example, boats can include an aft platform with a contoured underside that contacts water to generate such a wake for wake surfing. In some embodiments, the contoured underside of the platform includes dual opposing wake-shaping surfaces that shape the water flowing aft from the boat hull to create a wake shape that is well-suited for wake surfing. The aft platforms can be integrally manufactured as an extension to the hull or deck of a new boat, or manufactured separately and subsequently affixed to a previously manufactured boat.

Abstract: A standup paddleboard outrigger includes a long, narrow, lightweight displacement hull and a pair of outrigger pontoons mounted to a bridge. The two parts disengage for easy storage and transport. The hull has a platform to stand on. Paddling with a long handled paddle propels the craft through the water. The outriggers provide lateral stability/support and actuate the rudder in order to make turns. When a person stands on the platform and shifts body weight, the rudder will rotate to the right and the craft will turn to the right. The more weight that is shifted, the greater the turning action. The responsiveness to the shift of body weight can be adjustable for personal preference either firmer or more flexible, as is the turning response of the rudder fine or coarse turning.

Abstract: In a first aspect, a multi-hull platform boat comprises an upper deck or platform that is secured to a plurality of longitudinally extending hulls via a plurality of corresponding longitudinally extending connectors. Each connector extends from the bottom of the platform above a corresponding hull. The platform is constructed with a continuous uninterrupted planar lower support spanning the area between the connectors. The lower support is preferably made from one or more moldable materials and may be covered with a finish coating. In a second aspect, a multi-hull platform boat has a platform with a relatively planar upper support surface and a wedge-shaped base extending from the upper support surface of the platform to the bottom of the hulls. The base is wedge-shaped such that it increases in height from the front to the rear of the boat.

Abstract: An arch shaped structural member suitable for use as a wakeboard tower including a pair of legs and a crosspiece supported by the legs, both of the legs and the crosspiece being a coreless cast structural member characterized as a cast structural member and devoid of a hollow interior enclosed by solid portions.

Abstract: A vessel includes an outboard motor including an upstream exhaust port that emits exhaust, a hull including a rear portion on which the outboard motor is mounted, a cabin disposed above the hull, a downstream exhaust port disposed farther to a lateral side than the outboard motor, and an exhaust passage extending from the upstream exhaust port to the downstream exhaust port and guiding the exhaust from the upstream exhaust port to the downstream exhaust port. The cabin includes a windshield disposed in front of the outboard motor in a plan view. The height of the cabin from a rearmost end of the outboard motor is not less than ½ or about ½ of a horizontal distance in a front/rear direction from a rear end edge of the windshield to the rearmost end of the outboard motor.

Abstract: A water bike using a floating bodies and a driving housing is provided. Some implementations of the disclosed technology provide the water bike including a plurality of floating bodies each of which has a spherical shape or a sphere-like shape and disposed at front and rear sides of the water bike, connection rods that are attached to or detached from the floating bodies at positions toward centers of the floating bodies, a body frame for connecting the plurality of floating bodies to one another, a driver chair disposed over the body frame, handles configured to manipulate a moving direction and connected to a rudder that is disposed at a rear side of the water bike, and pedals disposed on the body frame adjacent to the floating body that is disposed at the front side to provide a driving force.

Abstract: The present invention is a water wings device used in combination with a watercraft that includes a plurality of water wings attached to the sides of the watercraft with attachment arms and directing fins that are placed into the water that the watercraft is traveling in. There is also an embodiment of the water wings device that includes a boat tail with a tapering protrusion that is placed into the water the watercraft is traveling in. Another embodiment is the water tail device that includes a plurality of water tails that attach to the rear of portion of a watercraft used in conjunction with water wings on the side of the watercraft that are all placed into the water the watercraft is traveling in.

Abstract: An improved trimaran of a type having a central hull, a starboard outrigger, a port outrigger, a starboard crossbar for attaching the starboard outrigger laterally to the starboard of the central hull, and a port crossbar for attaching the port outrigger laterally to the port of the central hull is provided. The improvement comprises a starboard propulsor attached to the starboard outrigger for propelling the trimaran, a port propulsor attached to the port outrigger for propelling the trimaran; and a motor controller connected to both the starboard and port propulsors for controlling the combined propulsion of the starboard and port propulsors for controlling both the speed and direction of the trimaran by tank steering.

Abstract: A marine vessel comprising: a command module; first and second buoyant tubular foils; and first and second struts for connecting the first and second buoyant tubular foils to the command module, respectively; wherein the first and second buoyant tubular foils provide substantially all of the buoyancy required for the marine vessel; and wherein the marine vessel further comprises first and second engines enclosed within the first and second buoyant tubular foils, respectively, and first and second propulsion units connected to the first and second engines, respectively, for moving the marine vessel through the water.

Abstract: Boats and suspensions are provided, wherein the boat includes at least one hull, and at least one sponson, the at least one hull and at least one sponson connected by a shock-absorbing suspension member. The suspension greatly reduces the accelerations of the main hull, such that the hull accelerations are generally substantially less than the accelerations of the sponsons at selected speeds.

Abstract: A hydrofoil craft, particularly a method of economically modifying a conventional hull with cambered foils to obtain and calculate increased lift from dense spray and to achieve enhanced craft performance is disclosed. The present invention improves speed, fuel efficiency and rough water stability, reduced pitch and vertical accelerations. A catamaran or V-bottom hull is modified with chine mounted airfoils, flexible dihedral cambered foils positioned beneath the water line and on either side of the bow so as to create turbulence in the forward end of a tunnel(s). Tunnels are created on the V-bottom hull by the chine mounted airfoils. Fixed forward tunnel cambered foil(s) and/or fixed or adjustable center tunnel cambered foils at the stern end of the tunnel to generate lift from pressure caused by dense spray in the tunnel(s) may also be provided. Adjustable cambered stern foils are mounted on the transom end of the tunnels.

Abstract: The invention relates to an accessory for a watercraft, the watercraft including a body including a bow having an end, a stern and two sides, extending between the end of the bow and the stern, including gunwales at an upper edge. The accessory includes a body means adapted to lie substantially along the length of one side, substantially proximal to the gunwales. In use, two accessories are used, so that a body means lies substantially along the length of each side of the watercraft, and the body means are configured so as to provide increased flotation of the watercraft in the water. The invention also relates to an accessory for a watercraft which acts as a fender, reduces splash or spray, or increases lift of the watercraft as it moves through water. The invention also relates to a method of installing an accessory on a watercraft.

Abstract: A high performance human powered boat is disclosed which centers around an articulating aiko and hand-actuated skimming planning outriggers. While the craft is in the static mode, flotation from amavons (combination of traditional ama and elevons) supply static buoyancy; while in interim speeds, amavons skim or plane across the water surface, In optimum performance, small retractable and variably applied skimmers or sweepers (similar to sweep stroke in rowing) control the roll of the craft on an as-needed basis. All of the planning both intermediate and with sweepers is done with potentially less drag than with traditional aikos and displacement amas.

Abstract: A watercraft suitable for operation in rough water conditions is disclosed. The watercraft comprises a central platform (13) and two pairs of hull units (60), a forward pair and an aft pair. The hull units are located on opposite sides of tie platform and extend below the platform, with each hull unit comprising a mount (54) attached to the platform and a trailing hull connected to the mount via a movable hull support. The components of the hull units are connected by joints (58,62) arranged to constrain lateral and axial movement of: the hull relative to the platform (12) but to permit pivoting thereof about the mount (54). Each hull unit has a suspension assembly arranged to support the respective hull units, and comprises a suspension member (66) extending from the platform (12) to a mounting point (20) on the hull aft of the respective mount, and being arranged to accommodate movement of the hull relative t) the platform and to apply damping to movement of the hull.

Abstract: The present technical solution provided allows it to determine true meridian of any movable object. This solution is based on determining true meridian by zero value of linear acceleration induced created by changing the projection of the vector of linear velocity, caused by rotating any heavenly body, in particular, the terrestrial globe. The determination is implemented in compact variant only by the devices located on the movable object without any necessity of using induced radiations, quickly and accurately without any necessity of knowing the coordinates of location and the speed of movement irrespective of weather conditions, transverse accelerations, temperature changes and external magnetic fields influence.

Abstract: A pontoon for a watercraft. The pontoon has a vertical inboard side and a generally angled bottom defined by the inboard side height of the pontoon being greater than its outboard side height. The bottom has planing surfaces that define one or more channels, which produce lift upon the watercraft increasing its speed on water. An inboard horizontal planing surface allows relatively low speed planing.

Abstract: A device (1) for converting a monohull vessel (2) into a multihull vessel, includes a support structure (3) which is removably fixed to the vessel (2) and at least one lateral float (4) which is solidly articulated with the support structure (3) around at least one geometrical axis (BB?). The aforementioned float (4) can occupy (i) a first stable deployed position in which it is parallel to the vertical longitudinal geometric plane (PP?) containing the keel line of the vessel (2) and, at the lowest point of the keel line thereof, it is disposed beneath the geometric axis (BB?) and (ii) a second stable collapsed position which is separated at an angle from the first position. A vessel equipped with the device is also disclosed.

Abstract: A multihull hydrofoil watercraft incorporates a stabilization system wherein the buoyancy of the hulls is used as a sensing and control mechanism for the hydrofoils. The use of hull buoyancy to adjust the hydrofoil lift provides for automatic control of altitude, pitch and roll, and allows the craft to accommodate varying weather and sea conditions while providing a smooth ride for passengers. The stabilization technique eliminates the need for extraneous sensing mechanisms placed in or on the water surface which are subject to fouling, damage, or disruption by localized surface disturbances.

Abstract: A ski structure for use with a boat hull to support the hull above the water when the boat is underway, the ski structure comprising an air tight housing in the form of an inverted U-shaped shell and a floor which forms a main ski surface and which extends between opposite sides of the U-shaped shell. The ski structure also includes a pair of assist skies or glides positioned lower than the main ski surface which extend substantially the length of the shell and which are adapted to plane on the surface of the water.

Abstract: A small outboard motor powered boat comprises a hull undersurface that defines a generally flat central section, with two generally parallel-sided pontoons extending rearwardly from an upturned bow to a point about half the length of the hull aft. A stern rake section begins at a transverse line near the transom of the hull and forms a downward angle with respect to the flat central section. At speed, air is entrained between the pontoons, providing lift to the bow of the vessel, while the after portion is supported by the stern rake section. Thus, the vessel effectively rides on the pontoons and the stern rake section, reducing wetted surface and thus improving efficiency. The downwardly-extending lengthwise sides of the pontoons provide lateral surface, providing good steering characteristics.

Abstract: A pontoon for a watercraft. The pontoon has a vertical inboard side and a generally angled bottom defined by the inboard side height of the pontoon being greater than its outboard side height. The bottom has planing surfaces that define one or more channels, which produce lift upon the watercraft increasing its speed on water. An inboard horizontal planing surface allows relatively low speed planing.

Abstract: A planing pontoon hull is described including a bow section with separate steep and shallow bow planes separated by left and right displacement guides extending upward from a planar bottom. Forward bow angle, steep deflections angles, displacement angles, and shallow planing angles are described for water movement over a range of water speeds and depths.

Abstract: A small planing watercraft can have a hull, an engine, and a steering assembly. The steering assembly can be configured to be translatable in the fore and aft direction, as well as pivotable about a generally horizontal axis so as to provide more flexibility in accommodating different. Optionally, a watercraft can include moveable members on a bottom surface of the hull so as to change a turning characteristic of the watercraft.

Abstract: A watercraft (100) is disclosed having a rigid hull (110) and outboard stabilizing members (112) attached to the hull sides (116). The hull preferably has a V-shaped bottom (118) and comprises a planing hull. The stabilizing members are preferably foam stabilizers, but may alternatively be inflatable bladder members. The stabilizing members cover a portion of the hull sides, extending part way to the chine (120) defined between the hull sides and the hull bottom. The stabilizing members each include an elongate fin (130) that extends from a bottom surface of the stabilizing member, and disposed in a front portion of the stabilizing member and in the region of the greatest hull dead rise angle. The fins may be formed integrally with the stabilizing members or may attach to the stabilizing members. The fins define a channel between the hull sides and the fins, that is hydrodynamically pressurized during certain watercraft operations, an in particular during low speed maneuvering.

Abstract: A hydrofoil craft, particularly a method of economically modifying a conventional hull with cambered foils to obtain and calculate increased lift from dense spray and to achieve enhanced craft performance is disclosed. The present invention improves speed, fuel efficiency and rough water stability, reduced pitch and vertical accelerations. A catamaran or V-bottom hull is modified with chine mounted aerofoils, flexible dihedral cambered foils positioned beneath the water line and on either side of the bow so as to create turbulence in the forward end of a tunnel(s). Tunnels are created on the V-bottom hull by the chine mounted aerofoils. Fixed forward tunnel cambered foil(s) and/or fixed or adjustable center tunnel cambered foils at the stern end of the tunnel to generate lift from pressure caused by dense spray in the tunnel(s) may also be provided. Adjustable cambered stern foils are mounted on the transom end of the tunnels.

Abstract: The invention is a marine wing-in-ground effect vehicle capable of sustained high speed operation in varying seas. The vehicle comprises an aerodynamic flat bottom lifting wing with a fuselage, a longitudinal keel member under the wing, a propulsion unit installed in the keel member, a vertical stabilizer airfoil mounted on top of the wing, and an overturn prevention tail at an aft end the wing. Port and starboard surface foils are pivotably mounted under the wing, and taper from a wider front end to a substantially narrow trailing end. The surface foils are selectively and independently pivoted between a deployed position and a retracted position by an actuator.

Abstract: A small boat has left and right sponsons extending in a longitudinal direction and respectively attached to left and right side walls forming a boat body. The sponsons are provided with an attachment section contacting a left side wall, a gliding section extending substantially horizontally from a lower edge of the attachment section, an inclined section connecting to a side edge of the gliding section, an upper edge of the attachment section, and projecting sections extending from an upper edge to a lower edge of the inclined section. Water flowing along the inclined section is guided by the projection sections and removed or separated from the inclined section. Accordingly, a small boat that turns through a small arc turning locus is provided, e.g., a small boat that is capable of relatively tight turning.

Abstract: Stabilizing apparatus have particular application in stabilizing smaller water borne objects such as small dinghies, sail craft, pontoons and aquatic sporting equipment at rest on a body of water, or any aquatic vessel including launches. The stabilizing apparatus includes a body having one or more elongate stabilizing pods including at least one cavity for containing a calculated volume of air. The body is attached to a side and towards the rear of the water borne object, in the region of the plane of the waterline of the object. The stabilizing apparatus operates between a non-use, storage position and an extended operating position and includes latching apparatus to maintain the body in either or both those positions.

Abstract: Disclosed is an AFIFD mounted on the front surface and both side surfaces of an amphibious vehicle to provide additional buoyancy. The AFIFD allows safe swimming of the amphibious vehicle, provides rapidity through automated folding and unfolding processes. The AFIFD has a membrane structure having a seal function and a plate structure having protection power, which are organically combined with each other, to provide both a seal function and protection power. The AFIFD is provided with air while being unfolded by the operation of driving means when the amphibious vehicle swims in water, so that the membrane structure and the plate structure are unfolded to form a completely sealed floating space. When the amphibious vehicle does not swim in water, the structures are folded and closed fixed to a vehicle body, so that the amphibious vehicle can run on ground without any difficulty.

Abstract: A watercraft has at least two narrow hulls with a shallow draft and has one or more passive flotation devices that are entirely submerged. The hulls enclose the power trains for the watercraft and are accessible from the compartments of the watercraft. The passive flotation devices do not include a power train or any other equipment requiring access from the compartments of the watercraft. The narrow, shallow draft hulls have low friction drag and produce a small bow wave. Thus, the watercraft is able to be propelled rapidly, to be propelled for a greater distance, and to be propelled efficiently by the power provided by smaller motors and lighter energy sources.

Abstract: The vessel has a pair of flexible hulls flexibly coupled to a “cabin” between and above the hulls, thereby allowing the hulls to independently follow the surface of the water. Motor pods are hinged to the back of the hulls to maintain the propulsion system in the water, even if the stern of one or both hulls tends to lift out of the water when crossing swells and the like. Various other embodiments and features are disclosed.