Patent Document

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&#39;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. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a watercraft and hull in accordance with an embodiment of the present invention. 
       FIG. 2  is a back perspective view of a watercraft and hull of  FIG. 1 . 
       FIG. 3  is a schematic bottom view of an embodiment of a hull design according to the invention. 
       FIG. 4  is a schematic bottom view of an alternate embodiment of a hull design according to the invention. 
       FIG. 5  is a schematic bottom view of an alternate embodiment of a hull design according to the invention. 
   

   DETAILED DESCRIPTION 
   Reference will now be made in detail to an embodiment of the invention as illustrated in the accompanying drawings. 
   Turning to  FIGS. 1–2 , an embodiment of a watercraft, generally identified by reference number  10 , is illustrated. The watercraft  10  comprises a hull  12  having a bow  14 , stern,  16 , port side  18 , and starboard side  20 . The watercraft  10  may be built out of aluminum with a formed hull or sheets with welded seams. The hull  12  and other portions of watercraft  10  could also be fabricated from other materials such as, for example, FRP, high-density polyethylene, other metals, or other suitable materials. 
   As illustrated in  FIGS. 1 and 2 , and with reference to the schematic of the hull configuration in  FIG. 3 , the watercraft  10  comprises a hull  12  which 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 hull  12  further reduces lateral action on the hull which produces pitching. The hull  12  is of a multi-hull configuration, having first and second outer deep V-hulls  22  (only one shown in  FIG. 1 ) and a central wave-deflecting hull  24 . The hulls  22  and  24  each have a unique configuration to allow the above advantages to be realized. A gunwale  15  is mounted above hull  12 , and a windshield  17  is mounted above the gunwale and toward the bow  14 . The gunwale  15  has side rails  19 , forming a passenger compartment for use of the boat  10 . A motor mount  21  is provided for mounting of a boat motor  23  to propel the watercraft  10 . 
   The hull portions  22  and  24  each have a very narrow profile, and outer hulls  22  each have a pointed V-shaped front-end wave spreading edge  26 . The central hull  24  extends forward of the outer hulls  22 , and has a wave spreading structure  25  associated therewith. The extent that the central hull  24  extends forwardly of the outer hulls  22  can vary depending on the size of the watercraft  10 , and the type of water body the craft is designed to operate in. In general, the central hull  24  length may be from between 5to 25% or more greater than the outer hull lengths. With reference to  FIG. 3 , the hull  24  is configured to have a substantially flat bottom portion  28 , with a front end  30  defined by a substantially vertically oriented wedge shape. The front end  30  would normally be exposed to oncoming waves, but in the present invention, the wave spreading structure  25  deflects any waves away from the portion  30 . This results in the hull portions  30  and  28  being recessed or internal to the wave contacting surfaces of the hull  12 . The wave spreading structure  25  may be formed of sheet material, configured into a wedge shape having first and second sides  32  and  34  and a front edge  36  directed forwardly. The sides  32  and  34  of 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 hull  12 . This also results in the boat  10  remaining substantially level as it moves across the water, even if waves or wake are encountered. Further, the boat  10  remains substantially level at different speeds when on plane, even if loaded. The sides  32  and  34  extend toward the rear of boat  10 , forming a cavity behind the front edge  36 . The sides  32  and  34  may extend to a position which is adjacent the position that water contacts the internal prow formed by the portions  28  and  30  as the boat  10  moves across the water. The sides also extend toward the water to a position just above the level of smooth water as the boat  10  moves through the water. 
   Each hull portion  22  is 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 portion  22  along with the wave spreader  25  associated with center hull  24 . From the front edges  26 , the hull portions  22  are formed to have substantially flat bottoms  40 , with a slight upward taper  27  formed at the forward end of each hull  22  to facilitate water displacement and planing of the boat during operation. The front edge  26  and forward side sections  29  of the hull portions  22  form v-shaped or wedge shaped portions which present somewhat vertically oriented wave spreading surfaces. Each hull portion  22  acts to spread waves laterally of the boat, and into the spaces  23  between hull sections. The spaces  23  between hulls  22  and  24  are designed to accommodate the volume of water displaced by the hulls based upon the size of the boat. 
   The hull portions  22  may extend to a position that is spaced rearwardly from the front of center hull  24 , such that oncoming wavers are first contacted by center hull  24 , and subsequently contacted by the hulls  22 . The hulls  22  are configured to cut through and deflect with minimal resistance, the initially deflected oncoming waves, before contacting the remaining portions of hull  12 . The hull portions  22  are 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 portions  22 . Oncoming waves are spread and directed immediately away from craft  10  by the substantially vertically oriented wedge surfaces  32  and  34  of hull portion  24 , and the surfaces  29  of hull portions  22 , which cut through and deflect water with less drag than other hull configurations. The height of the edge  26  of portions  22  may be suitable for the environment in which the watercraft  10  is to be used. Each front edge  26  on hulls  22  are 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 portions  22  may have a greater height. 
   Since the wave spreading configuration of each hull portion  22  and  24  is designed to deflect oncoming waves substantially horizontally, the wave-contacting surfaces  32  and  34  are 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 portions  22  and  24  may 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 spreader  25  will tend to deflect oncoming waves more upwardly and therefore increasingly drive the watercraft through the waves without substantial pitching of the hull. 
   Referring again to  FIG. 3 , and the hull portion  24 , there may be formed an air cavity  38  located rearwardly of the wave spreader  25 . The air cavity  38  facilitates 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 cavity  38  extends from the upper edges of the hull portion  24  and terminates at the internal hull prow  30 . Internal hull prow  30  comprises the forward end of the hull bottom, and extends rearwardly as a substantially flat-bottomed section  28 . In this embodiment, internal hull prow  30  is located at approximately sixty percent (60%) of the length of hull  12  as measured from the stern  14 , but lengths between approximately 50 to 90% are contemplated. The length of hull bottom  28 , and thus the location of internal hull prow  30 , 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 hulls  22  and  24 , generally, internal hull prow  30  encounters mostly smooth water. If desired to provide a further surface for deflection of any wave, the wave contacting surface planes of internal hull prow  30  may be formed in a slight v-bottom configuration, but forming a substantially flat bottom  28  toward the stern  16  of craft  10 . 
   The hull bottom  28  is located aft of the air cavity  38 . 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 portions  22  and  24 . As the surfaces  29 ,  32 , and  34  spread or deflect oncoming waves substantially horizontally away from the hull  12 , waves which would tend to cause a flat bottomed surface to pitch up are reduced significantly. 
   The hull bottoms  28  and  40  generally provide a large flat surface transitioning from the forward wave-deflecting surfaces or from internal prow  30 , 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 stern  16  of the craft  10 , the bottoms  40  of the outer hulls  22  extend to a position rearward of the rear wall or motor mount  21 , to extend the flat bottom surface which rides on the water during operation. The center hull  24  is then configured such that the bottom surface  28  terminates before reaching the stern. Water deflected by the wave deflecting surfaces of hulls  22  and  24 , is thereby channeled through the spaces  23  between hulls, and at the stern, only the outer hulls have bottom surfaces contacting the water, to provide a relief zone between hulls  22  at the rear of the craft  10 . An upwardly angled transition surface  46  extends from the stern to the bottom surface  28  at the rear of bottom surface  40  to the gunwale and back wall  21 . 
   In this embodiment of the watercraft  10  and hull  12 , each of the hull portions  22  and  24  has at its top end, upwardly angled transition surfaces  42  and  44 , extending from the apex  26 . If waves are encountered which extend up to this height, these surfaces  42  and  44  will also deflect waves away from the hull. Further, to facilitate stabilizing the craft  10  in the water, whether under power or at rest, each hull portion  22  and  24  may 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 to  FIG. 4 , an alternate embodiment of the hull configuration is shown at  100 , and again may comprise a central hull  104  and two outer hulls  102 , each of which has a wave spreading structure  105  associated therewith. In this embodiment, the wave spreading structure  105  of the outer hulls  102  and central hull  104 , extends to approximately the same forward position, such that each will engage and deflect waves. As in the prior embodiment, the hull portions  102  and  104  may be configured to have a substantially flat bottom portions  106  and  108 , with a upwardly tapered front ends  110  and  112  respectively. The front ends  110  and  112  would normally be exposed to oncoming waves, but in this embodiment, the wave spreading structures  105  deflect any waves away from the portions  110  and  112 . This results in the hull portions being recessed or internal to the wave contacting surfaces of the hull  12 . The wave spreading structures  105  may again be configured as a wedge shape having first and second sides  114 ,  116  and a front edge  118  directed forwardly. The sides  114  and  116  of 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  100 . This also results in the boat  100  remaining substantially level as it moves across the water, even if waves or wake are encountered. Further, the boat  10  remains substantially level at different speeds when on plane, even if loaded. The sides  114  and  116  extend toward the rear of boat  100 , forming a cavity behind the front edge  118 . The sides  114  and  116  may extend to a position which is adjacent the position that water contacts the internal prow formed by the portions  110  and  112  as the boat  10  moves across the water. The sides also extend toward the water to a position just above the level of smooth water as the boat  100  moves through the water. Each hull portion  102  and  104  acts to spread waves laterally, and into the spaces  120  between hull sections. The spaces  120  between hulls are designed to accommodate the volume of water displaced by the hulls based upon the size of the boat. 
   Turning to  FIG. 5 , an alternate embodiment of the hull configuration is shown at  150 , and may comprise first and second outer hulls  152  and  154 , each of which has a wave spreading structure  155  associated therewith. In this embodiment, the wave spreading structure  155  of the outer hulls  152  and  154 , 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 portions  152  and  154  may be configured to have a substantially flat bottom portions  156  and  158 , with a upwardly tapered front ends  160  and  162  respectively. The front ends  160  and  162  would normally be exposed to oncoming waves, but in this embodiment, the wave spreading structures  155  deflect any waves away from the portions  160  and  162 . This results in the hull portions being recessed or internal to the wave contacting surfaces of the hull. The wave spreading structures  155  may again be configured as a wedge shape having first and second sides  164 ,  166  and a front edge  168  directed forwardly. The sides  164  and  166  of 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 sides  164  and  166  extend toward the rear of boat  150 , forming a cavity behind the front edge  168 . The sides  164  and  166  may extend to a position which is adjacent the position that water contacts the internal prow formed by the portions  160  and  162  as the boat  150  moves across the water. The sides also extend toward the water to a position just above the level of smooth water as the boat  150  moves through the water. Each hull portion  152  and  154  acts to spread waves laterally, and into the spaces between hull sections. The spaces  170  between 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.

Technology Category: 7