Watercraft with wave deflecting hull

The invention is directed to a watercraft hull design that comprises a hull having a bow, stem, top, and bottom. A wedge-shaped wave spreading system is located at a forward portion of the craft. The wave-contacting surface planes of the wave spreading system are positioned substantially perpendicular to the plane of smooth water. The bottom edge of the wave spreading system is positioned near the level of smooth water when the watercraft is at cruising speed. The wave spreading system has a forward apex which forms a substantially perpendicular or vertical leading wedge to the plane of water. Since the apex and planes of the wave spreader are substantially perpendicular to the water, oncoming waves encountered by the wave spreader will tend to be deflected horizontally. Accordingly, the watercraft will more easily “cut through” waves instead of riding over them. Located rearwardly of the wave spreader, an internal hull prow is spaced from the wave spreading system, creating an air space therebetween. The air space extends from the rearward surface of the wave spreader to the front of internal hull prow, creating a buffer zone or dampening space to further minimize any wave action not detected by the spreading system.

TECHNICAL FIELD

The present invention relates generally to watercraft. More specifically, the present invention relates to watercraft hulls designed to displace water in a manner to provide enhanced stability and movement through the water.

BACKGROUND OF THE INVENTION

Conventional recreational and commercial watercraft, for the most part, incorporate hulls which have V-shaped bottoms, with the V-shape, at its lowest point, forming a keel. The V-shape is thought to enable the boat, as speed is increased, to be pushed upwardly out of the water, as the water traversing against the boat's bow is forced sideways and downwardly at a vector to the outer shape of the hull. Such designs have been used for years, but have various deficiencies.

One detriment to such hull designs is that the draft of the boat tends to sit relatively deep in the water in relation to the length and beam of the boat, thus requiring sufficient depth of water to accommodate that draft. Another detriment to such hull designs is that they require a relatively large amount of force (and horsepower) to propel such a boat forward at a sufficient speed to stabilize the boat, i.e., to force the water sideways and downwardly as the boat travels generally horizontally through the water.

With V-shaped hull designs, initially, as velocity begins to increase from zero, the bow of the boat acts much like a plow, digging into and through the surface of the water. This creates what is known as a “bow wave”. As velocity increases more, the bow tends to be forced upwardly by the sideways and downward force being applied to the water by the curvature of the V-shape of the hull being forced horizontally forward and up over the bow wave.

Finally, when sufficient velocity is approached and then reached, the apex of the force on the V-shaped hull travels aftwardly along the hull, forcing the boat more upwardly to an increasing degree until a point is reached at which the bow, now out of the water, tends, by force of gravity, to descend toward the water, pivoting on the apex of the force against the sides and bottom of the V-shaped hull. This pivoting serves to raise the stem of the boat as the bow descends until the whole boat is lifted upwardly into what is known as a planing position. At this point, because there is relatively less water contacting the hull, drag from that water is reduced and the boat is correspondingly able to go significantly faster given the same amount of force propelling the boat forward.

Of course, as might be anticipated, the hydraulic force of the water against the V-shaped hull is substantial, and thus at least an equally substantial counteracting force must be provided by the engine of the boat. Significant power is required to get the boat up to the planing position and to maintain it there. The ultimate speed of the boat, when planing, depends on the specific design of the V-shaped hull, the weight (and weight distribution) of the boat, and the available power, i.e., the size of the engine and the size and pitch of the propeller which is driven by the engine. However, in all cases, the forward movement of the boat, at any speed, whether up on plane or not, is counteracted by both sideways and downward vectors of force produced by the relative hydraulic movement of the water against the hull.

The amount of fuel needed to power a boat at a given velocity is in direct proportion to the overall degree of each of the forces needed to be overcome to move that boat forward over a given distance. The greater those forces, the greater will be the amount of fuel consumed. Thus as a general proposition, if fuel economy is a concern, hull designs are desirable which tend to reduce the overall amount of opposing forces directed against the hull during forward movement of the boat. One approach to this is the use of relatively flat bottom hulls wherein there is less counteracting hydraulic force imposed against the hull as the boat moves forward. A flat hull is more readily pushed directly up over the bow wave to a position substantially on top of the water, creating less displacement of water by the hull in the dynamic mode as distinguished from the static mode. In other words, dynamic displacement of water is significantly less with a flat bottom boat than with a V-shaped bottom. On the other hand, static displacement, when the boat is at rest, is substantially the same for a flat bottom or a V-bottom boat, given equivalent boat weights and hull surface contact with the water.

Watercraft or boats with flat bottom hulls have been known for years. Small fishing boats have been manufactured using this design. Such boats have a relatively shallow draft to enable sports fishermen to get into shallow waters along shorelines, into shallow, swampy areas, and into lakes, ponds and streams which are not sufficiently deep to accommodate the draft of conventional V-bottom boats.

Such designs have evolved into what are popularly called “bass boats”. Bass boat hulls are relatively narrow, in relation to length, with generally flat bottoms and relatively shallow V-shapes, if any. The draft of these boats is relatively shallow in comparison to V-shaped hulls. Once up on a plane, the vector force of the water is mostly downwardly, forcing these boats to rise up out of the water to a greater degree at relatively slower speeds, thus ultimate velocity can be greater, and relatively less engine power may be required to reach a given velocity.

The down side is that, because bass boats are relatively narrow beamed and because there is relatively little sideways or lateral force being exerted against the hull of a bass boat, there is correspondingly less lateral stability, and, due to a relatively narrow beam, such boats tend to be susceptible to laterally moving waves. Such flat bottom hulls are also generally more susceptible to waves as the hull rides more on top of the waves rather than slicing somewhat through waves as V-shaped hulls do to a greater degree. Also, such boats do not steer as easily or as precisely as those with distinct, V-shaped hulls, due again to the fact that such boats incur relatively less opposing sideways forces, being those forces which tend to hold a boat to a straight forward movement. Such forces if present can be precisely altered by a rudder device at the stem. Therefore, when steered to turn, bass boats tend to skid laterally sideways more readily, thus making turning a much less precise and controllable skidding action, rather than the positive, more precisely controllable action of V-shaped hulls. Bass boat designs rarely incorporate sponsons, thus, for the sake of safety, it is almost necessary to slow some high-powered bass boats down before turning, to both effect a more precise turn and to prevent the boat from flipping over.

Both types of hulls are susceptible to wave action and may produce instability depending on the height and direction of waves. Both types of hulls have large surfaces which absorb the force of waves, and cause significant vibration, vertical or lateral movement, or a combination of these. Other boats include hull designs which incorporate pontoons or sponsons for lateral stability and floatation, but such systems are undesirable for a number of reasons.

There is thus a need for a watercraft that overcomes the deficiencies of the prior art, and efficiently maneuverable in the water, while providing increased fuel efficiency and a smooth, stable ride, even in rough water.

SUMMARY OF THE INVENTION

The invention is therefore directed to a watercraft hull design that overcomes the deficiencies of prior designs. The watercraft comprises a hull having a bow, stern, top, and bottom. A wedge-shaped wave-spreading multi-hull at a forward portion of the craft. The wave-contacting surface planes of the wave spreading hull system are positioned substantially perpendicular to the plane of smooth water, at least adjacent the water surface.

The wave spreading hull portions have a forward apex which forms a substantially perpendicular or vertical leading wedge to the plane of water. Since the apex and planes of the wedge shaped hull portions are substantially perpendicular to the water, oncoming waves encountered by the hull portions will tend to be deflected horizontally. Accordingly, the watercraft will more easily “cut through” waves instead of riding over them.

Located rearwardly of the wave spreaders, an internal hull prow portion is spaced from the wave spreading surfaces, creating an air space therebetween. The air space extends from the rearward surface of the wave spreader to the front of internal hull prow, creating a dampening space to further minimize any wave action not deflected by the hull portions. The internal hull prow portion extends to a flat-bottomed section of the hull. The air space further eliminates any surface that would tend to ride up onto a wave.

The portion of the hull that contacts water while the watercraft is at cruising speed is spaced rearwardly of the air space. This portion of the hull that contacts the water is generally flat, as opposed to the V-shape commonly found in watercraft. This flat-bottomed hull enables the watercraft to easily reach a plane, while displacing a smaller amount of water than typical V-shaped hulls. The multi-hull design according to the invention also facilitates displacement of water between hulls, to further minimize forces acting on the boat.

DETAILED DESCRIPTION

Reference will now be made in detail to an embodiment of the invention as illustrated in the accompanying drawings.

Turning toFIGS. 1–2, an embodiment of a watercraft, generally identified by reference number10, is illustrated. The watercraft10comprises a hull12having a bow14, stern,16, port side18, and starboard side20. The watercraft10may be built out of aluminum with a formed hull or sheets with welded seams. The hull12and other portions of watercraft10could also be fabricated from other materials such as, for example, FRP, high-density polyethylene, other metals, or other suitable materials.

As illustrated inFIGS. 1 and 2, and with reference to the schematic of the hull configuration inFIG. 3, the watercraft10comprises a hull12which is designed to cut through waves or wakes of other boats, and minimize the forces acting on the hull to reduce the pounding experienced with typical hull designs. The hull12further reduces lateral action on the hull which produces pitching. The hull12is of a multi-hull configuration, having first and second outer deep V-hulls22(only one shown inFIG. 1) and a central wave-deflecting hull24. The hulls22and24each have a unique configuration to allow the above advantages to be realized. A gunwale15is mounted above hull12, and a windshield17is mounted above the gunwale and toward the bow14. The gunwale15has side rails19, forming a passenger compartment for use of the boat10. A motor mount21is provided for mounting of a boat motor23to propel the watercraft10.

The hull portions22and24each have a very narrow profile, and outer hulls22each have a pointed V-shaped front-end wave spreading edge26. The central hull24extends forward of the outer hulls22, and has a wave spreading structure25associated therewith. The extent that the central hull24extends forwardly of the outer hulls22can vary depending on the size of the watercraft10, and the type of water body the craft is designed to operate in. In general, the central hull24length may be from between 5to 25% or more greater than the outer hull lengths. With reference toFIG. 3, the hull24is configured to have a substantially flat bottom portion28, with a front end30defined by a substantially vertically oriented wedge shape. The front end30would normally be exposed to oncoming waves, but in the present invention, the wave spreading structure25deflects any waves away from the portion30. This results in the hull portions30and28being recessed or internal to the wave contacting surfaces of the hull12. The wave spreading structure25may be formed of sheet material, configured into a wedge shape having first and second sides32and34and a front edge36directed forwardly. The sides32and34of the wedge shape present substantially vertical surfaces to facilitate water displacement, resulting in a configuration that cuts through any waves, minimizing wave forces acting on the hull12. This also results in the boat10remaining substantially level as it moves across the water, even if waves or wake are encountered. Further, the boat10remains substantially level at different speeds when on plane, even if loaded. The sides32and34extend toward the rear of boat10, forming a cavity behind the front edge36. The sides32and34may extend to a position which is adjacent the position that water contacts the internal prow formed by the portions28and30as the boat10moves across the water. The sides also extend toward the water to a position just above the level of smooth water as the boat10moves through the water.

Each hull portion22is also formed with a large, somewhat vertical front edge profile, presenting the approaching water with a knife-edge type of profile. This edge cuts through any waves or wake and displaces water laterally of each hull portion22along with the wave spreader25associated with center hull24. From the front edges26, the hull portions22are formed to have substantially flat bottoms40, with a slight upward taper27formed at the forward end of each hull22to facilitate water displacement and planing of the boat during operation. The front edge26and forward side sections29of the hull portions22form v-shaped or wedge shaped portions which present somewhat vertically oriented wave spreading surfaces. Each hull portion22acts to spread waves laterally of the boat, and into the spaces23between hull sections. The spaces23between hulls22and24are designed to accommodate the volume of water displaced by the hulls based upon the size of the boat.

The hull portions22may extend to a position that is spaced rearwardly from the front of center hull24, such that oncoming wavers are first contacted by center hull24, and subsequently contacted by the hulls22. The hulls22are configured to cut through and deflect with minimal resistance, the initially deflected oncoming waves, before contacting the remaining portions of hull12. The hull portions22are designed such that the forward sections are positioned just above the smooth water level when the craft is in operation, such that smooth water will not impose substantial forces on the hull portions22. Oncoming waves are spread and directed immediately away from craft10by the substantially vertically oriented wedge surfaces32and34of hull portion24, and the surfaces29of hull portions22, which cut through and deflect water with less drag than other hull configurations. The height of the edge26of portions22may be suitable for the environment in which the watercraft10is to be used. Each front edge26on hulls22are designed to extend out of flat water to a height above any expected waves based on the size of boat and type of water bodies such a boat would be operated in. For example, for watercraft adapted for use in larger bodies of water with larger waves, the vertical height of the forward sections of portions22may have a greater height.

Since the wave spreading configuration of each hull portion22and24is designed to deflect oncoming waves substantially horizontally, the wave-contacting surfaces32and34are preferably substantially perpendicular, to the smooth water surface while the watercraft is at cruising speed. However, it is also contemplated that the wave-contacting surface planes of the portions22and24may be scooped or at a slight acute or obtuse angle to the smooth water while the watercraft is at cruising speed. For example, a slight obtuse angle between the plane of smooth water and the wave-contacting surface planes of the wave spreader25will tend to deflect oncoming waves more upwardly and therefore increasingly drive the watercraft through the waves without substantial pitching of the hull.

Referring again toFIG. 3, and the hull portion24, there may be formed an air cavity38located rearwardly of the wave spreader25. The air cavity38facilitates minimizing any pitching and pounding against the waves by eliminating forward hull surfaces that would tend to ride up on or pound against waves. The air cavity38extends from the upper edges of the hull portion24and terminates at the internal hull prow30. Internal hull prow30comprises the forward end of the hull bottom, and extends rearwardly as a substantially flat-bottomed section28. In this embodiment, internal hull prow30is located at approximately sixty percent (60%) of the length of hull12as measured from the stern14, but lengths between approximately 50 to 90% are contemplated. The length of hull bottom28, and thus the location of internal hull prow30, can vary further for more particular designs associated with different applications or environments within the scope of the present invention. Due to the wave spreading action of the hulls22and24, generally, internal hull prow30encounters mostly smooth water. If desired to provide a further surface for deflection of any wave, the wave contacting surface planes of internal hull prow30may be formed in a slight v-bottom configuration, but forming a substantially flat bottom28toward the stern16of craft10.

The hull bottom28is located aft of the air cavity38. A problem with conventional flat-bottomed watercraft has been their tendency to pitch and roll upon encountering waves. With the present invention, this problem is greatly reduced by the wave spreading hull portions22and24. As the surfaces29,32, and34spread or deflect oncoming waves substantially horizontally away from the hull12, waves which would tend to cause a flat bottomed surface to pitch up are reduced significantly.

The hull bottoms28and40generally provide a large flat surface transitioning from the forward wave-deflecting surfaces or from internal prow30, such that the hull displaces less water than conventional v-bottomed hulls at cruising speed. The smaller displacement of water enables the watercraft to cruise higher in the water, as compared to conventional v-bottomed watercrafts. Additionally, the watercraft leaves a smaller wake and requires less power for propulsion. Therefore, fuel economy is increased as compared to conventional v-bottomed boat hulls. Further, at the stern16of the craft10, the bottoms40of the outer hulls22extend to a position rearward of the rear wall or motor mount21, to extend the flat bottom surface which rides on the water during operation. The center hull24is then configured such that the bottom surface28terminates before reaching the stern. Water deflected by the wave deflecting surfaces of hulls22and24, is thereby channeled through the spaces23between hulls, and at the stern, only the outer hulls have bottom surfaces contacting the water, to provide a relief zone between hulls22at the rear of the craft10. An upwardly angled transition surface46extends from the stern to the bottom surface28at the rear of bottom surface40to the gunwale and back wall21.

In this embodiment of the watercraft10and hull12, each of the hull portions22and24has at its top end, upwardly angled transition surfaces42and44, extending from the apex26. If waves are encountered which extend up to this height, these surfaces42and44will also deflect waves away from the hull. Further, to facilitate stabilizing the craft10in the water, whether under power or at rest, each hull portion22and24may be formed in sections, with a lower section being substantially vertically oriented relative to smooth water, and upper sections which are angled outwardly to form a larger water displacing structure.

Turning toFIG. 4, an alternate embodiment of the hull configuration is shown at100, and again may comprise a central hull104and two outer hulls102, each of which has a wave spreading structure105associated therewith. In this embodiment, the wave spreading structure105of the outer hulls102and central hull104, extends to approximately the same forward position, such that each will engage and deflect waves. As in the prior embodiment, the hull portions102and104may be configured to have a substantially flat bottom portions106and108, with a upwardly tapered front ends110and112respectively. The front ends110and112would normally be exposed to oncoming waves, but in this embodiment, the wave spreading structures105deflect any waves away from the portions110and112. This results in the hull portions being recessed or internal to the wave contacting surfaces of the hull12. The wave spreading structures105may again be configured as a wedge shape having first and second sides114,116and a front edge118directed forwardly. The sides114and116of the wedge shape present substantially vertical surfaces to facilitate water displacement, resulting in a configuration that cuts through any waves, minimizing wave forces acting on the boat100. This also results in the boat100remaining substantially level as it moves across the water, even if waves or wake are encountered. Further, the boat10remains substantially level at different speeds when on plane, even if loaded. The sides114and116extend toward the rear of boat100, forming a cavity behind the front edge118. The sides114and116may extend to a position which is adjacent the position that water contacts the internal prow formed by the portions110and112as the boat10moves across the water. The sides also extend toward the water to a position just above the level of smooth water as the boat100moves through the water. Each hull portion102and104acts to spread waves laterally, and into the spaces120between hull sections. The spaces120between hulls are designed to accommodate the volume of water displaced by the hulls based upon the size of the boat.

Turning toFIG. 5, an alternate embodiment of the hull configuration is shown at150, and may comprise first and second outer hulls152and154, each of which has a wave spreading structure155associated therewith. In this embodiment, the wave spreading structure155of the outer hulls152and154, extend to a forward position of the hull, such that each will engage and deflect waves away from the other portions off hull. As in the prior embodiments, the hull portions152and154may be configured to have a substantially flat bottom portions156and158, with a upwardly tapered front ends160and162respectively. The front ends160and162would normally be exposed to oncoming waves, but in this embodiment, the wave spreading structures155deflect any waves away from the portions160and162. This results in the hull portions being recessed or internal to the wave contacting surfaces of the hull. The wave spreading structures155may again be configured as a wedge shape having first and second sides164,166and a front edge168directed forwardly. The sides164and166of the wedge shape present substantially vertical surfaces to facilitate water displacement, resulting in a configuration that cuts through any waves, minimizing wave forces acting on the boat. This also results in the boat remaining substantially level as it moves across the water, even if waves or wake are encountered. Further, the boat remains substantially level at different speeds when on plane, even if loaded. The sides164and166extend toward the rear of boat150, forming a cavity behind the front edge168. The sides164and166may extend to a position which is adjacent the position that water contacts the internal prow formed by the portions160and162as the boat150moves across the water. The sides also extend toward the water to a position just above the level of smooth water as the boat150moves through the water. Each hull portion152and154acts to spread waves laterally, and into the spaces between hull sections. The spaces170between hulls are designed to accommodate the volume of water displaced by the hulls based upon the size of the boat.

The foregoing disclosure is illustrative of embodiments of the present invention and is not to be construed as limiting thereof. Although one or more embodiments of the invention have been described, persons of ordinary skill in the art will readily appreciate that numerous modifications could be made without departing from the scope and spirit of the disclosed invention. As such, it should be understood that all such modifications are intended to be included within the scope of this invention. The written description and drawings illustrate the present invention and are not to be construed as limited to the specific embodiments disclosed.