Abstract: A thruster assembly to create shaped waves in a water behind a boat for water sports, such as wake surfing. The thruster assembly comprises one or more thrusting channels, an outer body the outer body comprises a round surface in the form of a circular or elliptical cross-section. The outer body comprises an elongated elliptical cross-section being wider than it is tall. A thruster portion comprises a width, a height, and a depth. The outer body comprises an outer surface and an inner surface. The outer body comprises a round surface in the form of a circular or elliptical cross-section. The outer body comprises an elongated elliptical cross-section being wider than it is tall.

Abstract: A fishing aid includes a housing with a hollow interior, an actuator being coupled to the housing, and an elevator. The elevator being in a pivotal connection with the housing and being in a coupling connection with the actuator, such that the elevator is configured, through the actuator, for a reciprocally pivotal movement in a vertical direction when the fishing aid is being pulled in a linear direction through a body of water by a line connected to the housing. The reciprocal pivotal movement of the elevator causes a movement of the fishing aid in a non-linear pattern through the body of water. The fishing aid can be used on a surface of the body of water or can be fully submerged with an aid of a downrigger.

Abstract: A watercraft with improved safety and stability is provided. The watercraft includes a shell defining a plurality of raceways for receiving water during certain maneuvers of the watercraft, thereby exerting force upon the watercraft in a first direction. The shell is configured so as to prevent or otherwise inhibit the water from exerting an opposed second force upon the watercraft. An intermediate panel of the shell provides increased flexibility, thereby serving as a shock absorber for the watercraft.

Abstract: A hull for a wakesurf boat includes an upper hull which is joined to a lower hull. The lower hull has a length, a maximum depth, a maximum width, a forward end, and an aft end. The lower hull is tapered toward the forward end and is largest at the aft end. In an embodiment, the maximum depth of the lower hull is less than 40% of the maximum width. In another embodiment the taper is a linear taper. The lower hull can include chines or can be rounded.

Abstract: A trim tab for a ship comprises a first portion and a second portion. The first portion is swingably mounted to a rear portion of a ship body. The second portion extends from the first portion and curves in a swing direction away from the ship body.

Abstract: A foil displacement system includes one or more foils that can be deployed and stowed. When deployed, each foil can exert downforce or uplift depending on its orientation. For example, each foil may be positioned to have an angle of attack that creates a downward force effectively transmitted to the hull to pull the hull deeper within the water to, for example, create a larger wake. Use of the foil displacement system can enhance or replace the use of a ballast tank system, can be integrated into a new boat or retrofitted to existing boats, can be electronically or manually positioned, can enhance activities such as wake surfing, wake boarding, water skiing or other similar or related water sports.

Abstract: A method of operating a boat to produce a surf wake includes partially filling a transverse ballast tank, moving the boat through a body of water, rolling the boat toward either its port or starboard side to shift the water in the transverse ballast tank such that at least some of the water in the transverse ballast tank moves from one side of a longitudinal centerline of the boat to the other side of the centerline, and creating a surf wake on the side toward which the boat is rolled.

Abstract: A staggered engine mount transom that extends from the primary engine mount transom of a boat for increasing the number of outboard engines mounted on a boat. A transom extension can include one or more supports for a transom section to which the outboard engines can be mounted. Engines mounted on a transom and a transom section can have overlapping operating widths and closer propeller center lines of propulsion. A transom extension can also have one or more engine pods in which outboard engines can be mounted so that the engine operating widths further overlap and the center lines of propulsion are even closer together. This allows more outboard engines to be mounted on a boat than can be mounted on just a single plane transom.

Abstract: A propeller-powered propulsion system and method of remote-controlled waterway navigation is configured to navigate a waterway in a navigation route while being controlled remotely, and being tracked by a GPS system. The watercraft provides a watercraft body that carries a propeller subassembly having multiple propellers that operate independently of each other for variable propulsion and steering. A mobile communication device transmits a command signal to a receiver in the propeller subassembly. A microcontroller converts the command signal to a speed for each propeller, independently of the other. The propeller speeds create a disproportionate level of thrust from each propeller to enable remote controlled steering of the watercraft toward port and starboard directions, at variable speeds, and preprogrammed navigation routes. The mobile communication device also acquires location data of the watercraft body obtained by a GPS system.

Abstract: A solar powered aquatic vessel includes a hull having an overall length equal to a length of a waterline and a maximum hull draft at station that is located at a position that is approximately 30% of the overall length of the hull. A bottom of the hull has an approximately linear slope from a maximum beam to a transom forming a stern of the hull. A canopy is connected to the hull of the solar powered aquatic vessel and supports at least one photovoltaic panel connected to a photovoltaic system positioned in the hull. The photovoltaic system generates electrical power from a sun that is equal to or greater than an electrical power necessary to propel the solar powered vehicle, and a motor operatively connected to the photovoltaic system.

Abstract: Provided is a hull of a boat including a central portion of a bottom of the hull, side portions of the bottom of the hull, lateral to the central portion of the bottom of the hull, the central portion of the bottom of the hull being substantially lowered in a substantially discontinuous way with respect to the side portions of the bottom of the hull, central side walls separating the central portion of the bottom of the hull from the side portions of the bottom of the hull. The hull also having external side walls laterally external to the side portions of the bottom of the hull.

Abstract: A helicopter uses electric propeller torque arm as power source directly driving main rotor to rotate. The helicopter may be battery powered. The helicopter may be without an engine, a clutch, a reducer, a tail driver, a tail boom, a tail rotor and a fuel supply system. The main design goal is to have the output shaft of the high-energy motor being coaxial with the main rotor shaft or having output shafts of a plurality of motors as close as possible to the main rotor shaft. The centrifugal force of the motor(s) is negligible or minimized. The torque arm assembly includes a plurality of torque arms. Each of the torque arm of the plurality of torque arms includes a propeller and a driving system. In the case of a malfunction, the helicopter's main rotor will spin like a maple leaf and will facilitate the spin autorotation landing.

Abstract: The invention is a watercraft with at least one hull which creates hydrodynamic lift by using narrowing concave channels (1) on the underside of the said at least one hull where propulsion (3) is placed such that the said propulsion draws water through the said narrowing concave channels (1).

Abstract: A boat hull having a design water line, the boat hull including a bow, a stern, a starboard side having a starboard chine and a starboard gunwale, a port side having a port chine and a port gunwale, a hull center line, and a bottom surface formed between the bow, the stern, the starboard chine and the port chine. The bottom surface includes first, second and third portions. The first portion is proximate the bow and includes a first concave surface and a second concave surface, the first concave surface projects from the hull center line towards the starboard chine and the second concave surface projects from the hull center line towards the port chine. The second portion is proximate the stern and includes a first convex surface and a second convex surface.

Abstract: A boat hull includes a pair of demi-hulls. Each demi-hull has a running surface configured to contact water when the hull is planing. The running surface extends longitudinally along a keel between an outer chine and an inner chine and aft to a running surface trailing edge. The running surface has most of its surface area outboard the keel. A first step extends laterally across the running surface and between the outer chine and inner chine. A first planing surface is aft the first step along the running surface. The first planing surface has an outboard convex curved surface on an outboard side of the keel extending from the keel to the outer chine and an inboard convex curved surface on an inboard side of the keel extending from the keel to the inner chine.

Abstract: A boat hull, comprising a plurality of chines extending downwardly from a bow of the hull towards a stern of the hull, each chine in transverse cross section being substantially straight and substantially horizontal and arranged so that a centerline of each chine lies in a plane which is parallel to a central plane of an adjacent chine, wherein collectively the chines in a lower forward portion of the hull are arranged generally V shaped in cross section and wherein an aft portion of a base of the hull is generally flat and each chine terminates at the flat aft portion.

Abstract: A suspension system for a marine vessel, the marine vessel including a body portion at least partially supported relative to at least a left hull and a right hull by the suspension system, the left and right hulls being moveable relative to each other and the body, the suspension system including resilient supports between the body portion and the left and right hulls. The suspension system providing at least a roll stiffness being arranged to provide a roll moment distribution (RMD) of the suspension system wherein roll forces effectively act at a position disposed within a longitudinal distance along the marine vessel from a steady state position of the resultant pressure forces acting on the left and right hulls when the marine vessel is operating in a planing or semi-planing mode. The longitudinal distance can be 20% or less of a waterline length of one of the at least a left and a right hull at design load in displacement mode.

Abstract: A method for creating a parametric planing hull model is disclosed. In one embodiment, dimensions of a plurality of hull sections, including two non-adjacent hull sections, are received from a user. Dimensions of at least one hull section between the two non-adjacent hull sections are interpolated. Curves of the hull are generated based on the dimensions of the plurality of hull sections received from the user and the interpolated dimensions of the at least one hull section between the two non-adjacent hull sections. Surfaces of the hull are created based on the generated curves, and a planing hull model is generated from the created surfaces and is displayed.

Abstract: A marine vessel hull, and marine vessels comprising at least one such hull, comprising a non-entrapment hull having at least one longitudinally vented transverse step, each longitudinally vented transverse step comprising a transverse step extending from starboard to port, and one or more longitudinal steps extending forward therefrom. One or more longitudinal steps may also extend aft of an aft-most longitudinally vented transverse step, and may converge to a relatively lesser depth at the stern than a maximum depth at a location fore of the stern. The one or more longitudinal steps may gradually transition to a maximum depth aft of a discontinuity introduced by a forward transverse step. The hull may also have one or more longitudinal step tunnels.

Abstract: A trolling motor mounting assembly for pivotally mounting a trolling motor includes a base that is configured to couple to a boat. A connector, which is hingedly coupled to a first end of the base, is configured to selectively couple to a shaft of a trolling motor. A first fastener is coupled to the connector. A bar is hingedly coupled to the base proximate to a second end of the base. A second fastener is coupled to a second endpoint of the bar. An actuator is coupled to the bar and is operationally coupled to the second fastener. The bar can position the second fastener to couple to the first fastener to fixedly vertically position the shaft. The actuator can compel the second fastener to decouple from the first fastener. The bar and the connector can pivot so that the shaft is parallel to the base and the bar.

Abstract: Pontoon hulls, devices, systems and methods for providing lower friction surfaces on the hulls to increase the efficiency of motorized pontoon boats moving through the water. The inner side walls and the tunnel ceiling surface between the pontoons in a motorized pontoon boat can be provided with a plurality of longitudinal vent channels in a U shaped configuration. The vent channels can have open ends facing the rear end (stern) of the water craft and opposite closed ends facing the forward end (bow) of the water craft. As the water craft moves forward, a bubbling effect can occur in low pressure zones about the rear (stern) facing open ends of the plurality of vents to reduce the water surfaces in contact with the pontoon hull surfaces.

Abstract: A foam product includes a foam core and a soft shell. The foam core includes a tightly packed cluster of expanded beads. Each of the expanded beads is made of a pre-expanded bead. The foam core defines in its top surface a recess. The recess has an inner wall on which some outermost beads of the expanded beads are exposed and protruded. The soft shell is disposed within the recess of the foam core and has an outer wall attached to the inner wall of the recess. In particular, the soft shell has at its outer wall a plurality of cavities sized and shaped to respectively receive the protruded, outermost beads in the recess of the foam core.

Abstract: A trimaran boat is provided. The trimaran boat may have a pair of sidehulls, a center hull positioned between the pair of sidehulls, and a deck extending substantially continuous from one sidehull across the center hull to the other sidehull. A trimaran boat hull is also provided. The trimaran boat hull may have a pair of sidehulls, a center hull positioned between the pair of sidehulls, a deck extending substantially continuous from one sidehull across the center hull to the other sidehull. The trimaran boat hull may also have a pair of center hull transitions and a pair of sidehull transitions. The trimaran boat may also be configured such that a transom of each sidehull is v-shaped.

Abstract: A wide beam, multi-hull icebreaker and method of operation thereof for opening a wide track through which large commercial vessels may traverse is disclosed. The icebreaker includes a plurality of hulls spaced apart and arranged generally in parallel to one another, with each of the hulls including a bow thereon configured to break through a sheet of ice through which the icebreaker traverses. The spaced apart hulls define at least one channel therebetween into which ice broken by the hulls is routed, and the hulls are spaced apart a distance such that a beam of the icebreaker is as wide as a beam of a commercial vessel it is servicing. A conveyor system may be included on the icebreaker that removes broken ice from the channel(s) between the hulls and casts it to the side of the track to leave a less dense track of broken ice.

Abstract: The invention concerns a vessel having a planing surface and a transom at a stern of the vessel, mounted on the transom is an interceptor and an actuator to move the interceptor in vertical direction. In accordance with the invention the transom defines a sharp edge with the planing surface and the underside of the interceptor comprises a convex rounded edge extending upwards to the rear with a leading edge of the convex rounded edge having a tangent approximately parallel to the water flow along the planing surface near the transom, and/or the transom defines a convex rounded edge with the planing surface with a leading edge of the convex rounded edge being tangent to the planing surface and the interceptor defines at its lowest part a sharp edge that can move behind the convex rounded edge in vertical direction.

Abstract: A Wiggle Hull design for a water vessel, the hull design including a planing hull segment. The planing hull segment has a longitudinal camber that is a combination of concave and convex undersurfaces for improving performance characteristics, including lift and lift to drag ratios. The Wiggle Hull design may also have end plates at the chines to optimize performance characteristics.

Abstract: A hovercraft without lift fan includes: a hull; and a power device; wherein the hull includes: a main body; and two sub-bodies; wherein bottom surfaces of the sub-bodies are lower than a bottom surface of the main body, the two sub-bodies are symmetrically aligned under a front portion of the bottom surface of the main body, the two sub-bodies are provided with a distance therebetween; an outer surface of the sub-body and an outer surface of the main body form an aligned side surface or an unified side surface; the aligned side surface or the unified side surface extends towards a space under the bottom surfaces of the main body and the sub-bodies for forming a main sidewall; an inner side surface of the sub-body extends towards a space under the bottom surface of the sub-body for forming a sub-sidewall.

Abstract: A keel pad is provided for a hull of a boat. The keel pad contains a main body and two fingers extending from the main body in a direction of a front of the hull. Due to curved shape of the fingers, drag is reduced allowing the boat better planing properties and greater fuel efficiencies.

Abstract: The invention concerns a vessel having a planing surface and a transom at a stern of the vessel, mounted on the transom is an interceptor and an actuator to move the interceptor in vertical direction. In accordance with the invention the transom defines a sharp edge with the planing surface and the underside of the interceptor comprises a convex rounded edge extending upwards to the rear with a leading edge of the convex rounded edge having a tangent approximately parallel to the water flow along the planing surface near the transom, and/or the transom defines a convex rounded edge with the planing surface with a leading edge of the convex rounded edge being tangent to the planing surface and the interceptor defines at its lowest part a sharp edge that can move behind the convex rounded edge in vertical direction.

Abstract: Planing hull extensions for watercraft are disclosed which may be mounted along the sides of the hull of a watercraft such as a boat or yacht. Typically, the hull extensions may be disposed along the side chines of the hull such that they extend the effective beam of the hull. The hull extensions may aid stabilizing the watercraft and/or inhibit wetting of the sides of the hull as well. In some cases, the hull extensions may be hydraulically operated between a closed position against the hull (or into a pocket along the side of the hull) and a fully open position substantially extending the width of the hull bottom. The position of the hull extensions may be automatically varied based upon throttle position, e.g. fully open at low throttle to fully closed against the hull at full throttle. Different hull extension position profiles may be used according to loading and water conditions.

Abstract: An improved watercraft hull providing stability and maneuverability in turns. The hull may include a longitudinal centerline extending from bow to stern, a first and second transverse air channel that are fluidly isolated from the rest of the hull, the first and second air channels separating the hull into a bow planing portion, a middle planing portion, and a stern planing portion, a first plurality of strakes protruding from the bow planing portion, a second plurality of strakes protruding from the middle planing portion, and a third plurality of strakes protruding from the stern portion. The hull may also include a V-shaped keel portion at the bow portion centerline, and a flattened hull portion at the stern portion centerline having a deadrise angle of 0°, the flattened hull portion being disposed between and directly adjacent to two adjacent longitudinal elements of the third plurality of longitudinal elements.

Abstract: Watercraft having a hull and a stern and including at least two additional floaters stretching out at the stern of a watercraft, wherein the additional floaters form a U at the stern of the watercraft, wherein the additional floaters and the hull each include bottoms and the bottoms of the additional floaters are positioned above the hull bottom, and wherein the bottoms of the additional floaters are stepped by one or more steps.

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 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 water, and means for reducing drag on the vessel as the vessel moves through water.

Abstract: A swim platform for mounting onto the stern of a boat. Generally, the swim platform includes an upper platform, a lower platform, and a central support member for interconnecting the platforms and for mounting the swim platform to the boat. The platforms are sized and configured such that one or more persons could comfortably stand or sit on them. A forward portion of the lower platform is disposed proximate a rearward portion of the upper platform. Also, the lower platform is spaced vertically below the top platform and is ideally positioned at or slightly above the surface of the water. In operation, as the boat accelerates, the lower platform tilts towards the water as the bow tilts upwards. As the lower platform contacts the water, an upward force is exerted onto the lower platform, which forces the bow downwards and simultaneously forces the stern up and out of the water.

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 hydroplaning vessel with several stability and handling design improvements. It has an enhanced reactive suspension and inner hull lift system positioned in the vessel between a set of separating inner and outer hulls. The outer hull does not float on its own as it has numerous fixed louvers formed there through and also has an open transom. Steering and braking are accomplished by a set of rear elevon flaps affixed to the outer hull. The drive unit resides in the inner hull and is connected by an annular drive transmission which is connected to the jet or prop drive which resides on the outer hull.

Abstract: A hull for a planing type watercraft has a front lift surface, a high lift surface, and a back planing surface. The high lift surface is adjacent a rockered keel area and between the front lift surface and the back planing surface. The center of dynamic lift on the high lift surface is at or in front of a point which is 15% of the hull length behind a total center of gravity of the hull under loading. At least the back one third of the high lift surface is cambered, and a beam of the high lift surface is greater than two thirds of the maximum width of the hull. The average camber of the front lift surface, the high lift surface, and the back planing surface together is less than or equal to zero.

Abstract: A submersible vessel comprising: an elongated hull; at least one propeller mounted on a forward end of said hull and adapted to move said hull through water; said at least one propeller being of a size and configuration such that when it is rotated at an appropriate speed, it generates supercavitated water flowing from said at least one propeller and then along an outer surface of said hull so as to diminish friction on the outer surface of said hull and facilitate high underwater speeds.

Abstract: A powerboat with a rooster tail depressor (RTD) includes a hull, a propulsion subassembly on the hull, and a rooster-tail-suppressing canopy on the stern that includes a downwardly facing surface no less than six inches above the dynamic water line of the stern where it functions to suppress the powerboat rooster tail for radar signature reduction and increased propulsion efficiency. Various embodiments include one or more of (i) a canopy having a downwardly facing surface that is arched (either curved or faceted), (ii) lift-to-drag ratio enhancing steps in the downwardly facing surface of the canopy, (iii) a rooster-tail-suppressing subassembly configured to enable articulation of the canopy in yaw and in trim, and (iv) operator-controlled port and starboard venting arrangements on the canopy that result in desired laterally directed thrust for enhanced maneuverability.

Abstract: A boat with several stability and handling design improvements. It has an enhanced reactive suspension system positioned in the vessel between a set of separating hull and body components. The boat also has improved braking, steering and stabilizing systems designed around multiple pivoting mechanisms on the vessel hull that work individually or in unison to achieve the desired braking or steering effect. The stabilizing system is operated by a computerized, gyroscopic hydraulic control to maintain stability and comfort of ride, minimizing the roll, pitch and yaw commonly experienced in the passenger compartment.

Abstract: Planing hull extensions for watercraft are disclosed which may be mounted along the sides of the hull of a watercraft such as a boat or yacht. Typically, the hull extensions may be disposed along the side chines of the hull such that they extend the effective beam of the hull. The hull extensions may aid stabilizing the watercraft and/or inhibit wetting of the sides of the hull as well. In some cases, the hull extensions may be hydraulically operated between a closed position against the hull (or into a pocket along the side of the hull) and a fully open position substantially extending the width of the hull bottom. The position of the hull extensions may be automatically varied based upon throttle position, e.g. fully open at low throttle to fully closed against the hull at full throttle. Different hull extension position profiles may be used according to loading and water conditions.

Abstract: A boat hull includes a bow, a stern and a bottom surface extending from said bow to said stern. Said bottom surface includes a substantially flat delta plate, and a keel extension extending, at least partially, across the delta plate.

Abstract: A wakesurfing boat includes a hull. A bottom of the hull defines a W-shape in cross-section, the W-shape including a central inverted V-shaped portion. A ballast system includes a plurality of sets of ballast tanks. The boat has a plurality of modes: a cruising mode with ballast tanks empty, a first portion of the bottom in contact with the water, a stern-down trim ?1; a ballasted static mode with ballast tanks filled with ballast water, the hull displacing more water, a larger portion of the bottom in contact with the water, a bow-down trim ?2; and a dynamic surfing mode with ballast tanks filled with ballast water, an intermediate portion of the bottom in contact with the water, and an intermediate trim ?3. A wake wave, generated in the dynamic surfing mode is larger than a wake wave generated in the cruising mode.

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: A method of fabricating a hydrodynamic appendage for a ship, the method including the steps of: forming two metal half-shells having outside surfaces that form the flanks of a hydrodynamically-active portion of the appendage; forming a metal head including a mechanism for securing the appendage to the ship; and assembling together the half-shells and the head so that the head is sandwiched between the top ends of the two half-shells and closes a top portion of an internal volume defined by the half-shells. The half-shells are welded to the head so as to make the internal volume watertight.

Abstract: A boat hull form includes a dual circular curved outer surface area that is circular concave relative to the plane of symmetry of the hull when viewed horizontally parallel with the plane of symmetry of the hull, and circular convex relative to the plane of symmetry when viewed vertically parallel with the plane of symmetry of the hull, with the hull outer surface area extending in a vertical sense from a lower area extending in a direction that tangentially intersects the plane of symmetry or optionally a plane extending parallel with the plane of symmetry on the same side of the plane of symmetry as the dual circular curved outer surface area and upwardly in a direction tangentially intersecting the waterline plane of the hull or a plane extending parallel to the waterline plane.

Abstract: An apparatus including a strake section having a plurality of helical fins separated by at least one helical opening. A method including forming a helically shaped fin that independently maintains the helical shape once formed.

Abstract: A system and method are provided for launching and recovering an unmanned, water-born vehicle (UWBV) from a mother ship. The UWBV mimics the behavior of dolphins and is positioned ahead of the ship in preparation for bow riding. The UWBV uses a guidance system to position and keep in the bow wave. A high-frequency (HF) sonar transceiver array aboard the ship computes and sends course corrections to maintain the UWBV within the bow wave. The frequency range of the HF array can be 100 kHz or higher due to the short distance between the ship and the UWBV. Accordingly, the HF array can have a small aperture allowing for accurate bearing resolution. Course corrections can be sent on a near-continuous basis such that changes in thrust and rudder angle can be minimized to allow for accurate control of the UWBV.

Abstract: Outboard engine unit includes: an anti-splash plate and an anti-cavitation plate provided on a gear case at a vertical interval from each other and extending horizontally from the gear case; an exhaust port provided in a side surface of the gear case for discharging exhaust gas from an engine; and a protruding section provided on the side surface of the gear case at a position located rearwardly of the exhaust port, the protruding section protruding laterally outwardly from the side surface for changing a direction of water flows flowing along the side surface.

Abstract: A boat hull (10) including a longitudinally extending side wall (12) and a longitudinally extending bottom wall (13). The side wall (12) has an internal surface (16), and the bottom wall (13) an internal surface (17). Fixed to the surface (16) and/or (17) is an insulation member (19) that inhibits the transmission of noise to the interior of the hull (10).