Abstract:
The present invention comprises dynamically operative keel systems and methods of enhancing a marine vessel&#39;s directional control, linear tracking, and turn holding, among other benefits. Hull undersurface facets, laterally symmetrically configured and disposed in laterally symmetrical pairs, extend longitudinally for varying extents establish longitudinally extending recesses and/or voids of varying cross-sections and/or depths that channel water flow and/or pressure. The facets generally include longitudinally extending laterally outermost, laterally innermost, and optional (in some embodiments), intermediate faces that demarcate the voids and/or recesses. The faces provide keel-simulating effects when the vessel is running on plane and travelling linearly or turning, and variously encounters uneven water surfaces, uneven and/or laterally/diagonally directed water surface pressures and/or currents, and/or laterally/diagonally directed winds.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation in part of and claims the benefit of the priority date of U.S. Non-Provisional Utility patent application Ser. No. 12/660,195, filed Feb. 22, 2010, and the entire disclosure of the parent U.S. Non-Provisional Utility patent application Ser. No. 12/660,195, is hereby incorporated herein by reference; in addition, this application is a continuation in part of U.S. Non-Provisional Utility patent application Ser. No. 11/408,524, now U.S. Pat. No. 7,677,192, filed Apr. 4, 2006, which is the parent application of the U.S. Non-Provisional Utility patent application Ser. No. 12/660,195, which is a continuation of U.S. Non-Provisional Utility patent application Ser. No. 11/408,524, and claims the benefit of its priority date; and the entire disclosure of the grandparent U.S. Non-Provisional Utility patent application Ser. No. 11/408,524, now U.S. Pat. No. 7,677,192, is hereby also incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    1. Field of the Invention 
         [0004]    The present invention primarily relates to controlling the direction of travel of a marine vessel when travelling on plane across a water surface, and in particular to enabling a planing marine vessel both to maintain an intended straight or turning trajectory when crossing an inhomogeneous water surface and to maintain a turning trajectory with reduced risk of spin-out or sideways slippage across the water. 
         [0005]    2. Related Art 
         [0006]    Marine vessels attempting to travel at higher velocity across a water surface achieve substantial gains in hydrodynamic drag reduction, efficiency, and speed produced for a given engine power output when the vessel&#39;s hull is travelling across the water on plane. When planing, the hull&#39;s contact area with and depth of penetration into the water surface are substantially reduced, enabling a speed of travel and efficiency that is not possible when floating in a displacement mode. However, the reduced contact and penetration depth can also impair the capacity of the hull to maintain directional control, both when traveling straight across uneven water and when effecting sharper turns without risk of spin outs or sideways slippage. The water surface a vessel travels across is rarely glass smooth, so that one side of the hull will frequently experience a differing drag than the other side, which would tend to turn the vessel even when it is attempting to travel in a straight line. Additionally, the vessel may encounter a water surface that presents diagonally angled wave fronts, such as another vessel&#39;s bow wave, and currents with sideways components that will tend to push a vessel off of a straight line, as well as significant sideways thrusting winds. 
         [0007]    A planing vessel generally effects a turn by utilizing the difference (within the general plane of the water surface) between the directional tracking of its hull and the direction of the prop/jet thrust (potentially augmented by the rudder-like effect of fins or similar structure that are often integrated with a prop housing.) When on plane the vessel&#39;s center of mass is generally disposed above the water line, while the vessel&#39;s roll orientation is at least partially constrained by its hull&#39;s wetted surface topography. The vessel&#39;s thrust angle is generally upward and forward in direction and is applied as a push action towards the rear portions of the vessel, so that when moving straight ahead variations in the upward angle of thrust (and sometimes the depth of thrust interaction with the body of water being traversed), are significant factors in determining the pitch of the vessel. When the vessel is to be turned, customarily the prop/jet thrust angle in the plane of the water surface is rotated, while its angle in the plane defined by the roll and yaw axes may also change, but usually remains upward. Hence, when turning, the thrust vector will tend to roll the vessel so that it leans into the turn (also termed heeling over), with the side on the inside of the turn lowered, and the outer side raised. The turn of the vessel as a whole as it travels across the water (as opposed to spinning out), in the plane of the water surface occurs because the vessel undersurface is configured to track straight in the vessel&#39;s longitudinal direction, analogous to a first direction an automobile&#39;s front wheels are heading when they rotate, while the thrust is in the rotated direction, analogous to a second, differing direction that the automobile&#39;s rear wheels are heading when they rotate. The undersurface configuring can include a variety of features, most commonly including a type of keel-forming profile, such as a V hull, wherein a longitudinally extended lowermost center rib has a longitudinally extending pair of rising hull undersurface portions on each side, such that the hull&#39;s resistance to movement through the water is substantially increased unless the movement is in the longitudinal direction. Further common sorts of longitudinal direction holding features are chines, strakes, and fins. 
         [0008]    The vessel is already travelling across the water surface with a reduced depth of penetration when planing, with the commencement of a turn rolling the vessel so that it typically is riding more on only one side of the hull, if a monohull, or one side of one sponson (or at least fewer than all of the sponsons) of a multihull. This orientation will tend to produce a further lessening of the depth of penetration of the water surface, because more of the hull (or sponson) side surface contacts/displaces the water surface, and hence provides support against gravity, and this side surface is generally flatter than an equivalent portion of the hull that is centered on the central rib of the hull or sponson keel form. In addition, the features of the vessel hull undersurface that are configured to provide directional control by resisting sideways movement across the water surface are designed to be most effective when the vessel is in a zero-roll orientation, and thus progressively lose their resistance as the vessel roll increases. The vessel is traveling across the water surface in a first bearing at a high speed when on plane, and the commencement of a turn produces a relatively quick reorienting force on the vessel towards a second bearing, while the majority of the vessel&#39;s momentum is still in the direction of the first bearing. The vessel is thereby being pushed into an at least partial sideways movement across the water, which as noted earlier the vessel hull&#39;s undersurface features are at a reduced capacity for resisting. Among the negative outcomes of this situation, when the vessel hull&#39;s resistance to the sideways force is insufficient for the degree of turn being commenced, are a spin-out, in which the vessel hull&#39;s directional control substantially fails, or a sideways slipping across the water surface in which the vessel&#39;s orientation changes too slowly, so that the vessel continues an excess of movement in the direction of the first bearing, while being pointed more in the second bearing, and hence turns too slowly to maintain the desired trajectory. 
         [0009]    Hence, it is desirable to develop aspects of a marine vessel hull undersurface that can enable a planing vessel to track a desired straight or turn trajectory with reduced tendencies for undesired non-linear tracking and/or spinout and/or insufficient turn tracking caused by sideways slippage across the water surface. 
       SUMMARY OF THE INVENTION 
       [0010]    In order to provide enhanced linear and/or turn tracking, while avoiding impairing performance when not turning whether on or off plane, the present invention has been developed. Most embodiments of the present invention involve pairs of hull facets that are laterally symmetrically disposed and configured, and include hull undersurface upwardly indenting recesses that are also laterally symmetrical in disposition and configuration. Normally, the facet pairs are longitudinally extended, though the lengths can vary depending on the embodiment, and more than one facet pair can be employed with each pair potentially being similar or having differing longitudinal dispositions which may be overlapping, and/or differing lengths, and/or differing lateral positions, and/or differing lateral cross-sections. The lateral cross-sections of any of the hull facets and/or recesses can be substantially steady throughout the facet&#39;s or recess&#39; length, can vary for some portion of its length, or can include an assortment of varying and unvarying cross-sections. Most often, these variations will not include a significant longitudinally extended substantial reduction of the recess cross-sectional area, or diminishing depth of indentation of the recess as the recess progresses rearward so as to avoid impairing straight line performance and/or efficiency. 
         [0011]    The height of the upward indentations of a more rearward portion of a facet&#39;s recess generally increases or remains the same as a more forward portion, but usually does not decrease as the recess progresses rearward for a major fraction of the longitudinally extending recess. Among the included recess indentation height variations are differing rates of increase, and/or combinations of steady and increasing indentation heights, and/or multiple transitions between steady and increasing indentation heights, and/or combinations that include multiple differing rates of indentation height increases, but do not usually include indentation heights that decrease for a major fraction of the recess length. Additionally, more forward portions encompassing a major fraction of a recess&#39; length usually do not encompass greater cross-sectional areas than do more rearward portions of that recess. A significant instance in which a more rearward portion will encompass a lessening cross-sectional area and/or diminishing indentation depth than a more forward portion will occur when a recess&#39; longitudinally rearward terminus is forward of the transom, and does not end at hull step. The majority of vessel hulls do not included a hull step, and for those hulls, a longitudinally mid hull disposed facet recess will normally include a length of increasing and/or steady recess cross-sectional area and/or indentation depth, with an ending length of diminishing depth and/or cross-sectional area. 
         [0012]    A facet generally includes longitudinally extending first laterally outermost and second laterally innermost faces that at least partially demarcate that facet&#39;s recess. The lowermost portion of the first laterally outermost face normally meets an immediately adjacent portion of the hull (or sponson) undersurface that has a deadrise angle that is inclined upward in the lateral outward direction, while the lowermost portion of the second laterally innermost face meets the hull undersurface at position that is inward of the first laterally outermost face&#39;s meeting with the hull undersurface. One or more intermediate faces may be laterally disposed between the first laterally outermost face and the second laterally innermost face, and any of the faces can have a partially or fully linear or arcuate trajectory, or combinations thereof, when viewed in a planar side to side cross-section. Variations in facet and/or recess width are essentially unlimited, except for the constraints that the first laterally outermost faces of a facet pair are separated by more than a quarter of the vessel&#39;s beam, while the second laterally innermost faces are separated by at least 4% of the vessel&#39;s beam. 
         [0013]    In the majority of embodiments, the immediately inwardly adjacently hull undersurface has a lesser deadrise angle than does the lowermost portion of the second laterally innermost face. The lowermost portion of first laterally outermost face has, at minimum, a lesser deadrise angle than the immediately outwardly adjacent portion of the hull undersurface, and may often be inclined substantially upward in the laterally inward direction, up to a vertical or even past vertical inclination. Frequently, the lowermost portions of the first laterally outermost face and the second laterally innermost face will have differing inclinations to vertical, and often the lowermost portions of the first laterally outermost face will be inclined closer, sometimes much closer, to vertical than the lowermost portion of the second laterally innermost face. However, the full range of the embodiments of the present invention do encompass, when a specific implementation calls for it, instances wherein the second laterally innermost face has a similar or even greater inclination relative to horizontal than the first laterally outermost face. In general, as the vessel heels over during a turn the first laterally outermost face will progressively present substantially greater resistance to laterally outward sideways movement of the water surface across the hull undersurface, and thereby provide a dynamically effected turn tracking enhancement. When traveling linearly across uneven water, the longitudinally extending first laterally outermost face and second laterally innermost face will tend to enhance straight tracking even when the water surface is moving with a sideways component, is exerting an imbalanced impact on the hull sides, is diagonally inhomogeneous, and/or the vessel is being pushed with a sideways wind component. 
         [0014]    A first embodiment of the present invention involves dynamically operative keel-simulating facets of a marine vessel hull undersurface, comprising one or more symmetrically disposed pairs of hull facets, said facet pairs including laterally symmetrical, hull undersurface recesses formed with a longitudinally extending laterally outermost first face and a longitudinally extending laterally innermost second face having lowermost portions that are laterally inclined at first and second angles, respectively, relative to a horizontal vessel deck, said first and second angles having a differing inclination to the horizontal than the respective immediately adjacent non-recess portions of the hull undersurface, wherein a more forward portion of a major longitudinal recess fraction does not indent the vessel hull inwardly farther than does a more rearward portion of said major longitudinal recess fraction, and lowermost portions of each of the pairs&#39; outermost first faces and innermost second faces are laterally separated, respectively, by more than a first greater fraction and more than a second lesser fraction of the marine vessel&#39;s beam. 
         [0015]    A first variant of the first embodiment involves a substantial longitudinal fraction of at least one of said recesses indenting the vessel hull by a generally unvarying depth. A second variant of the first embodiment involves one or more relatively rearward portions of at least one of said recesses indenting the vessel hull farther inwardly than does a more foreward portion of that recess. A third variant of the first embodiment involves said first greater fraction being more than a quarter of the vessel&#39;s beam. A fourth variant of the first embodiment involves said first greater fraction being selected from a group consisting of, a) more than 26% of the vessel&#39;s beam; b) more than 30% of the vessel&#39;s beam; c) more than ⅓ of the vessel&#39;s beam; d) more than 40% of the vessel&#39;s beam; e) more than 50% of the vessel&#39;s beam; f) more than ⅔ of the vessel&#39;s beam; g) more than ¾ of the vessel&#39;s beam; and e) more than 90% of the vessel&#39;s beam. 
         [0016]    A fifth variant of the first embodiment involves said second lesser fraction being more than 2% of the vessel&#39;s beam. A sixth variant of the first embodiment involves said second lesser fraction being selected from a group consisting of a) more than 4% of the vessel&#39;s beam; b) more than 5% of the vessel&#39;s beam; c) more than 10% of the vessel&#39;s beam: d) more than 20% of the vessel&#39;s beam; e) more than ¼ of the vessel&#39;s beam; f) more than ⅓ of the vessel&#39;s beam; g) more than ½ of the vessel&#39;s beam; h) more than ¾ of the vessel&#39;s beam, and i) more than 80% of the vessel&#39;s beam. A seventh variant of the first embodiment involves the outermost first faces of at least one of said facet pairs being laterally inclined upward at greater angles relative to the horizontal vessel deck than are that facet pairs&#39; innermost second faces. An eighth variant of the first embodiment involves the outermost first faces of at least one of said facet pairs being laterally inclined upward at an angle greater than 75 degrees relative to the horizontal vessel deck. A ninth variant of the first embodiment involves the outermost first faces of at least one of said facet pairs being laterally inclined upward at an angle within 5 degrees of being perpendicular to the horizontal vessel deck. 
         [0017]    A tenth variant of the first embodiment involves, when measured in a lateral planar section, the outermost first faces of at least one of the facet pairs&#39; spanning a lesser absolute distance than does that facet pairs&#39; innermost second faces. An eleventh variant of the first embodiment involves said recesses&#39; indenting the vessel hull inwardly by no more than a first maximum recess depth, said first maximum recess depth chosen from a group consisting of: a) 2% of the vessel&#39;s beam; b) 4% of the vessel&#39;s beam; c) 8% of the vessel&#39;s beam; d) 12% of the vessel&#39;s beam; e) 15% of the vessel&#39;s beam; f) 5% of the vessel&#39;s resting draft; g) 10% of the vessel&#39;s resting draft; h) 20% of the vessel&#39;s resting draft; i) 30% of the vessel&#39;s resting draft; k) 40% of the vessel&#39;s resting draft; and l) 50% of the vessel&#39;s resting draft. A twelfth variant of the first embodiment involves one or more of said recesses further including one or more intermediate faces laterally disposed between said outermost first and innermost second faces. A first sub-variant of the twelfth variant of the first embodiment involves at least one of said intermediate faces being laterally inclined generally parallel to said horizontal vessel deck. A second sub-variant of the twelfth variant of the first embodiment involves at least one of said intermediate faces being laterally inclined generally parallel to said horizontal vessel deck. A third sub-variant of the twelfth variant of the first embodiment involves at least one of said one or more recesses includes a single bridging intermediate face, said bridging intermediate face being laterally inclined at third and fourth angles relative to said first outermost and second innermost faces, respectively, of that recess, and said third angle being greater than said fourth angle. A fourth sub-variant of the twelfth variant of the first embodiment involves at least one of said one or more recesses including a single bridging intermediate face, said bridging intermediate face being laterally inclined at third and fourth angles relative to said first outermost and second innermost faces, respectively, of that facet pair, and said fourth angle being greater than or equal to said third angle. 
         [0018]    A thirteenth variant of the first embodiment involves one or more portions of at least one of the outermost first, the innermost second, and an optional one or more intermediate faces laterally disposed between the outermost first and the innermost second faces, of at least one of said pairs of recesses having a laterally arcuate surface topography. A fourteenth variant of the first embodiment involves at least one of said one or more facet pairs including a single bridging intermediate face, said bridging intermediate face being laterally inclined at third and fourth angles relative to said first outermost and second innermost faces, respectively, of that facet pair, and said third angle being greater than said fourth angle. A fifteenth variant of the first embodiment involves at least one of said facet pairs having a longitudinal extent of less than 90% of said vessel&#39;s waterline length. A sixteenth variant of the first embodiment involves at least one of said facet pairs having a longitudinal extent being selected from a group consisting of a) less than 80% of the vessel&#39;s waterline length; b) less than ¾ of the vessel&#39;s waterline length; c) less than 60% of the vessel&#39;s waterline length; d) less than 50% of the vessel&#39;s waterline length; e) less than ⅓ of the vessel&#39;s waterline length; f) less than ¼ of the vessel&#39;s waterline length; and g) less than 10% of the vessel&#39;s waterline length. A seventeenth variant of the first embodiment involves at least one of said facet pairs&#39; longitudinal extent having a rearmost reach that ends forward of the vessel&#39;s transom, and said forward of transom ending facet pair potentially rearwardly terminating at a longitudinal hull position that does or does not coincide with a hull step. And an eighteenth variant of the first embodiment involves at least first and second of said facet pairs, wherein said first and second facet pairs have dissimilar longitudinal extents, said dissimilar longitudinal extents varying by one or more of having differing forwardmost reaches, differing rearwardmost reaches, and said first facet pair&#39;s rearwardmost reach being forward of said second facet pair&#39;s forwardmost reach. 
         [0019]    A second embodiment of the present invention involves a method of managing a marine vessel hull undersurface&#39;s turning hydrodynamics with offset keel-simulating facets, comprising the steps of counteracting sideways water surface flow, when turning said vessel while on plane, by interrupting said flow with longitudinally extending, inwardly facing, outermost first faces of one or more laterally symmetrical facet pairs that upwardly indent the marine vessel&#39;s undersurface with recesses that are at least partially demarcated by a longitudinally extending innermost second face and said outermost first face, wherein lowermost portions of the first and second faces are laterally inclined at first and second angles, respectively, relative to a horizontal vessel deck; inducing longitudinally directed water surface flow by channeling said flow along said recesses&#39; longitudinally extending void, wherein the upward indentation of a more forward portion of a major longitudinal fraction of the void does not indent the vessel hull inwardly farther than does a more rearward portion of said major longitudinal fraction of the void; influencing, with said second face, any sideways water surface flow to enter the recess for interrupting by the first face and longitudinal channeling along the void, wherein said first and second faces are separated by more than a first greater fraction and more than a second lesser fraction of the vessel&#39;s beam, respectively; and arranging at least one of said facet pairs&#39; dispositions so that when the vessel turns while on plane and rolls its inner-turn side downward, the proportion of the vessel&#39;s weight born by the first and second faces and the recess of the inner-turn side facet of the at least one of said facet pairs is increased. 
         [0020]    A first variant of the second embodiment of the present invention involves the first greater fraction being more than a quarter of the vessel&#39;s beam. A second variant of the second embodiment of the present invention involves the second lesser fraction being more than 4% of the vessel&#39;s beam. A third variant of the second embodiment of the present invention involves the first greater fraction being more than a quarter of the vessel&#39;s beam. And a fourth variant of the second embodiment of the present invention involves each facet of at least one of said facet pairs being symmetrically arranged on separate sponsons of a multi-hull vessel, with each of the sponson facet recesses&#39; laterally outermost first faces being disposed laterally outwards of each of their respective sponsons&#39; lowermost longitudinally extended portion. 
         [0021]    A third embodiment of the present invention involves a method of configuring a marine vessel hull undersurface with dynamically operative keel-replicating facets, comprising the steps of disposing laterally symmetrically one or more pairs of hull facets that include hull undersurface recesses, demarcating said recesses with a longitudinally extending laterally outermost first face and a longitudinally extending laterally innermost second face having lowermost portions that are laterally inclined at first and second angles, respectively, relative to a horizontal vessel deck, said first and second angles having a differing inclination to the horizontal than the respective immediately adjacent non-recess portions of the hull undersurface, such that a more forward portion of a major longitudinal recess fraction does not indent the vessel hull inwardly farther than does a more rearward portion of that said major longitudinal recess fraction, and, and laterally separating each of the symmetrically paired recesses&#39; outermost first faces and innermost second faces, respectively, by more than a first greater fraction and more than a second lesser fraction of the marine vessel&#39;s beam. 
         [0022]    A fourth embodiment of the present invention involves a multi-hull marine vessel undersurface having one or more pairs of laterally symmetrical dynamically effective turn-holding facets, comprising one or more symmetrically disposed pairs of hull facets, said facet pairs including laterally symmetrical, hull undersurface recesses formed with a longitudinally extending laterally outermost first face and a longitudinally extending laterally innermost second face having lowermost portions that are laterally inclined at first and second angles, respectively, relative to a horizontal vessel deck, said first and second angles having a differing inclination to the horizontal than the respective immediately adjacent non-recess portions of the hull undersurface, and a more forward portion of a major longitudinal recess fraction does not indent the vessel hull inwardly farther than does a more rearward portion of that said major longitudinal recess fraction; wherein said facet pair&#39;s recesses are each arranged on differing laterally separated sponsons of said multihull, with each of the recesses&#39; laterally outermost first faces disposed laterally outwards of each of their respective sponsons&#39; lowermost longitudinally extended portion. A first variant of the fourth embodiment of the present invention involves the lowermost reach of each of the outermost first faces of at least one of the facet pairs extending no farther downward than a lateral line inclined upward at 5 degrees to horizontal from inward to outward, said lateral line passing through the sponson&#39;s lowermost reach. A second variant of the fourth embodiment of the present invention involves at least one of said one or more facet pair recesses further including one or more intermediate faces disposed between the outermost first and innermost second faces. A third variant of the fourth embodiment of the present invention involves, for at least one of said pairs of recesses, one or more portions of at least one of the outermost first, the innermost second, and an optional one or more intermediate faces laterally disposed between the outermost first and the innermost second faces having a laterally arcuate surface topography. 
         [0023]    A fifth embodiment of the present invention involves a method of managing a marine vessel hull undersurface&#39;s directional tracking hydrodynamics with offset keel-simulating facets, comprising the steps of maintaining at least one of said vessel&#39;s longitudinal orientation and longitudinal direction of travel when the vessel, while running on plane, experiences one or more of laterally asymmetrical water flow, laterally asymmetrical water distribution, and laterally asymmetrical atmospheric effects, said maintaining involving configuring the hull undersurface with longitudinally extending, inwardly facing, outermost first faces of one or more laterally symmetrical facet pairs that upwardly indent the marine vessel&#39;s undersurface with recesses that are also at least partially demarcated by a longitudinally extending innermost second face and said outermost first face, wherein lowermost portions of at least one of the first and second faces are laterally inclined upward at first and second angles, respectively, relative to a horizontal vessel deck, and wherein the upward indentation of a more forward portion of a major longitudinal fraction of the void is not more than the upward indentation of a more rearward portion of the major longitudinal fraction of the void; inducing one or more of longitudinal vessel orientation, relative to the intended direction of vessel travel, and longitudinally directed water surface flow, relative to the vessel&#39;s longitudinal axis, by constraining the water flow into channeling along said recesses&#39; longitudinally extending voids; and influencing diagonally directed, relative to the vessel&#39;s longitudinal axis, water surface pressure with one or more of said first and second faces, to be redirected by one or more of the first and second recess faces into longitudinal channeling along the void, wherein said first and second faces are separated by more than a first greater fraction and more than a second lesser fraction of the vessel&#39;s beam, respectively. 
         [0024]    Other objects and features will be in part apparent and in part pointed out hereinafter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  depicts forward facing rear end views of a double facet pair first embodiment of the present invention that also includes a central slot aspect. 
           [0026]      FIG. 2  depicts a partial forward facing rear end views of a double facet pair second embodiment of the present invention that also includes a central slot aspect. 
           [0027]      FIG. 3  depicts a schematic upward plan view of a hull undersurface of a third embodiment of the present invention that depicts three variations of potential facets that are shown in a partially depicted combination arrangement for clarity of illustration. 
           [0028]      FIG. 4  depicts a side perspective view of a single mid-hull facet pair fourth embodiment of the present invention. 
           [0029]      FIG. 5  depicts a partial expanded side perspective view of a mid and fore hull double facet pair fifth embodiment of the present invention. 
           [0030]      FIG. 6  depicts a schematic partial rear cross-section view of a bi-faced single facet pair catamaran sixth embodiment of the present invention. 
           [0031]      FIG. 7  depicts a schematic partial rear cross-section view of a tri-faced single facet pair catamaran seventh embodiment of the present invention. 
           [0032]      FIG. 8  depicts a schematic partial rear cross-section view of a partially arcuate faced single facet pair catamaran eighth embodiment of the present invention. 
           [0033]      FIG. 9  depicts an elevated rear quarter perspective view of a bi-faced single facet pair catamaran ninth embodiment of the present invention. 
           [0034]      FIG. 10  depicts a side perspective view of a transom reaching single extended facet pair tenth embodiment of the present invention. 
           [0035]      FIG. 11  depicts a rear perspective view of a single facet pair eleventh embodiment of the present invention further depicting a variety of dimensional relationships. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0036]    In the following description, identical numbers indicate identical elements. Where an element has been described in one Figure, and is unaltered in detail or relation in any other Figure, said element description applies to all Figures. 
         [0037]      FIG. 1  shows a combination schematic/perspective forward facing view of the rear of a dual facet pair and slot marine vessel first embodiment  110  of the present invention. The vessel transom  112  includes a longitudinally extending laterally centered slot aspect defined recess  114 . Immediately adjacent the central slot aspect recess  114 , the vessel hull undersurface first section  116  extends laterally outward at a first deadrise angle. The outer edge of first section  116  meets a longitudinally extending dual planar faced first recess  118  at the lowermost inward boundary of its innermost second face  120 , which extends outward to its longitudinally extending outermost first face  122  at its uppermost level  124 . A vessel hull undersurface second section  126  extends laterally outward at a second deadrise angle from the lowermost boundary of the outermost first face  122 . The outer edge of second section  126  meets a longitudinally extending triple planar faced second recess  128  at the lowermost inward boundary of its innermost second face  130 , which extends outward to a longitudinally extending horizontal intermediate third face  132  that defines the uppermost level of recess  128 . An outermost second face  134  defines the outward reach of the second recess  128 , and at its lowermost portion meets the outermost hull undersurface third section  136  that is inclined at a third deadrise angle, and extends outward to the hull side  138 . An alternative upwardly inclined recess second laterally innermost face  140  and broader intermediate face  142  (not shown on the left side of  FIG. 1 ), are utilizable as well for the providing of improved straight line tracking, such as when an uneven water surface causes, at least momentarily, only one side of the hull to be significantly engaged with the water surface. When such a circumstance is occurring, and a diagonally inwardly directed water pressure is being applied to the vessel hull by that uneven water surface, the steeply inclined second laterally innermost face  140  will serve to longitudinally channel said diagonal water pressure and aid the vessel to maintain its straight line tracking, similarly to how the first laterally outermost face  134  will aid straight line tracking in analogous circumstances with diagonally outward directed water pressure. 
         [0038]    When running on plane, the vessel hull will tend to ride across the surface of the water, rather than penetrate the water to a greater depth as when in a displacement mode. The side walls of the slot aspect recess  114  provide a degree of straight line tracking assistance when the vessel is on plane, as well as a small amount of cornering aid when the vessel is turning slightly by inhibiting sideways slippage of the hull across the water surface, with the left side wall aiding a left turn and the right aiding a right turn. The slot aspect recess  114  though is relatively shallow, and when a moderately significant right turn is effected, the vehicle will heel over readily enough so that the first section  116  becomes approximately horizontal. When traveling straight, the downward slope of the two sides of the first sections  116 , though limited, is sufficient to increase the water depth penetration of the slot aspect recess  114  somewhat, even when on plane, and thereby enable the two sides of the recess to aid tracking across the water surface. But when heeled over so that the first section  116  is horizontal it will provide a substantially greater amount of support and hence will reduce the penetration of the hull into the water surface substantially as well. The deadrise angle of first section  116  varies in differing embodiments of the present invention, as is illustrated in  FIG. 2  as well as others, with the deadrise angle of the first section  116  in the first embodiment  110  being at an angle to the horizontal (which is essentially the plane of the water surface) that when extended outward, will be above the downward reach of the lowermost portion of the right outermost first face  122 . Hence the right outermost first face  122  will substantially interrupt any sideways rightward outward movement of the water surface across the hull undersurface, with the first recess  118  collecting water under pressure and channeling its flow in a longitudinally extending direction. 
         [0039]    The innermost second face  120  has a much closer to horizontal inclination than does the closer to vertical outermost second face  122 , which can also be inclined (not shown) at an outwardly lesser descending slope or at a vertical, or past vertical slope (also not shown), since any inclination it has will be increased as the vessel heels over during a turn. The lesser inclination of the innermost second face  120 , and its modest change in slope from that of the first section  116 , both helps to provide further support of the vessel upon the water surface along with the first section  116  when the vessel is heeled over and facilitates the turn holding impact of the outermost first face  122 . The height of the outermost first face  122  is relatively large, and while the scope of the present invention does encompass even greater outermost first face&#39;s  122 , in many embodiments the height will be even less, while still providing substantial turn holding effects. 
         [0040]    For the exemplary embodiment illustrated in  FIG. 1 , the deadrise angle of the second section  126  is greater than that of the first section  116 , though it is within the scope of the present invention for this difference in deadrise angle to be reversed, or leveled so that there is no difference. The greater deadrise angle of the second section  126  when extended outward crosses the second recess  128  outermost second face  134  above its lowermost reach. The second recess  128  has a substantially lesser cross-section than the first recess  118 , as defined by its lesser height outermost second face  128  and its height limiting intermediate third face  132 . For when the vessel is executing an extreme turn, the amount of heel over will bring both the first recess  118  and the second recess  128  into turn holding action. While the presently illustrated embodiments show either one (in the case of an arcuately demarcated recess), two, or three faces demarcating the recesses that provide the dynamically operative keel simulating effect, the scope of the present invention encompasses any number of faces, in principle. Additionally, the relative sizes, variations in planar and arcuate topographies of, and relative inclinations of the recess demarcating faces encompassed by the scope of the present invention are all unlimited in principle, except for those circumstances wherein a particular combination would interfere with the providing of the keel-simulating effect during a turn when on plane. Moreover, varying combinations of multiple facet pairs, such as the parallel dual pairs of laterally more inwardly disposed recesses  118  and more outwardly disposed recesses  128 , are encompassed within the scope of the present invention. These multiple facet pairs are, in principle, unlimited in number, indisposition other than being laterally symmetrical and of longitudinally extending configuration, in width beyond constraints to the separation of the lowermost portion of each pair&#39;s respective most inward and outward faces, in length, in longitudinal location including multiple distinct recesses separated along the hull&#39;s length and/or multiple parallel recesses of differing and/or overlapping longitudinal positions, or in depth beyond the constraint that a more forward portion of a major longitudinal recess fraction does not indent the vessel hull inwardly farther than does a more rearward portion of that said major longitudinal recess fraction, and in some cases no more forward portion of a recess will indent the hull inwardly more than a more rearward portion of that recess. 
         [0041]      FIG. 2  shows a combination schematic/perspective forward facing view of the rear of a dual facet pair and slot marine vessel second embodiment  210  of the present invention. The vessel transom  212  includes a longitudinally extending laterally centered slot aspect defined recess  214 . Immediately adjacent the central slot aspect recess  214 , the vessel hull undersurface second embodiment first section  216  extends laterally outward at a fourth deadrise angle. The outer edge of the second embodiment first section  216  meets a longitudinally extending dual planar faced first recess  218  at the lowermost inward boundary of its innermost second face  220 , which extends outward to its longitudinally extending outermost first face  222  at its uppermost level  224 . A vessel hull undersurface second embodiment second section  226  extends laterally outward at a fifth deadrise angle from the lowermost boundary of the outermost first face  222 . The outer edge of the second embodiment second section  226  meets a longitudinally extending triple planar faced second recess  228  at the lowermost inward boundary of its innermost second face  230 , which extends outward to a longitudinally extending horizontal intermediate third face  232  that defines the uppermost level of recess  228 . An outermost second face  234  defines the outward reach of the second recess  228 , and at its lowermost portion meets the outermost hull undersurface second embodiment third section  236  that is inclined at a sixth deadrise angle, and extends outward to the hull side  138 . 
         [0042]    Individually, and in combination, the deadrise angles of the second embodiment first section  216  and second section  226  are less than those of the first embodiment first section  116  and second section  226 , though it is within the scope of the embodiments of the present invention for one or more of the second embodiment sections to be of greater dead rise angle than those of the first embodiment, or to have alternating combinations of greater and lesser dead rise angle, as well as a greater or equal net deadrise angle for the hull as a whole. Furthermore, the outermost first face  222  and third face  234  are have lesser heights than do the first face  122  and third face  134 , respectively, though these differences can also vary and or alternate between lesser and greater and still fall within the scope of the present invention. The third face  234  is also somewhat inclined outward and downward, rather than close to vertical, but it should be understood that this variation is strictly illustrative, and is not limiting. Essentially any variation in inclination of any of the recess demarcating faces also falls within the scope of the present invention, and the particular examples shown are purely illustrative and not limiting. As shown in  FIG. 2 , the first recess  218  and second recess  228  both have lesser heights and lesser cross-sectional areas than do the first recess  118  and second recess  228 , respectively. There are also potential differentiation between a recess with a lesser height, and a recess with a lesser cross-sectional area, such as the area  238  of the second recess  228 . The area  238  of the second recess  228  is a factor of its maximum height, but is also determined by its width, as well as the particular geometry of its demarcating faces, and variations in which a specific recess has a lesser height but a greater cross-sectional area also fall within the scope of the present invention. 
         [0043]    Further variations of the arrangements of the facet pairs and their interrelations with differing hull configurations that fall within the scope of the present invention are illustrated by contrasting the first embodiment  110  with the second embodiment  210 . The net overall deadrise angle of the second embodiment  210  hull is less than that of the first embodiment  110  hull, so that the second embodiment  210  hull penetrates the water depth to a lesser extent than the first embodiment  110  hull. Hence, the second embodiment  210  hull will tend to heel over to a lesser degree for a turn of the same magnitude, but due to its lesser deadrise angle, the first recess  218 , and then the second recess  228  will engage with any sideways water surface movement, and thereby effect the turn tracking enhancement, sooner than would the first recess  118  and then the second recess  228  for that amount of turn of the first embodiment  110  hull. Hence, the first recess  218  and the second recess  228  can be effective with lesser heights of the outermost first face  222 , and third face  234 , as well with lesser recess  218  and recess  228  cross-sectional areas than for the corresponding features of the first embodiment  110 . 
         [0044]    A schematic, purely illustrative under hull plan view of a multi-single-facet embodiment  310  of the present invention incorporates unpaired examples of three differing forms of fact configuration that individually can each be incorporated into a symmetrical fact pair included within an embodiment of the present invention. As shown in  FIG. 3 , the depicted facets are not arranged in symmetrical facet pairs, and could not be actually all employed in facet pairs without interfering with each other, hence the multi-single-facet embodiment  310  should be considered to be a combination of incompatible left and right side examples of potential facet configurations. In  FIG. 3 , the vessel hull fraction depicted as the left side (upper side as shown), includes a hull step, while the vessel hull fraction depicted as the right side (lower side as shown), is free of hull steps. An elongated rectangle first facet plot  312  extends rearwardly to its end at the transom, and begins at a forward squared off leading edge  314 . Its outermost first face  316  is essentially vertical, and hence is only seen as an edge in  FIG. 3 . The first facet plot  312  recess is demarcated by the first face  316 , an innermost second face  318  that is laterally inclined upward (when the vessel is in its normal operating orientation), and outward at a moderate angle from its innermost edge outward to an intermediate edge  320 , and a laterally generally horizontal intermediate face  322  which extends outward from the intermediate edge  320  to the outermost first face  316 . 
         [0045]    Also depicted in  FIG. 3  are an oblique facet  324  with a recess demarcated by dual faces. The oblique facet  324  initiates from an obliquely angled forward initiating edge  326 . The oblique facet  324  has an outermost moderately sloped first face  328  that extends upward and inward at an angle between 45 and 85 degrees, with the most common choices being made between 45, 66⅔, 75, or 85 degrees, (though specific vessel employments of facet pair embodiments according to the present invention may find it advantageous, depending on the particular circumstances, to variously utilize a wide range of inclinations for the first face  328 , which could differ from each other by as little as 5 degrees, across the entire range of 15 to 85 degrees.) An oblique facet innermost second face  330  is broader than the first face  328 , and it is generally inclined less than the first face  328 . The rearmost reach of the oblique facet  324  extends to the of a hull step vertical face  332 . The hull step functions as a planing surface, and hence when turning while on plane, the recess, and especially the first face  328 , of the oblique facet  324  can function vary similarly to the corresponding recess  118  and outermost first face  122 . A triangular plan facet  334  is composed of an steeply inclined outermost first face  336  and a generally much less inclined innermost second face  338 . 
         [0046]    A side perspective view of a longitudinally mid-hull middle-step facet pair embodiment  410  shown in  FIG. 4  depicts a representative example of a step-length facet disposition  412  that is longitudinally situated entirely within a second step  414  of a dual step hull, and could be in principal any of a number of differing facet cross-sections and/or plans, when configured of a suitable length, such as any of the elongated rectangle first facet plot  312 , the oblique facet  324 , and/or the triangular plan facet  334 , as well others. 
         [0047]    An expanded detail side perspective view of a longitudinally separated non-step fore hull, and mid hull step dual facet pair embodiment  510  shown in  FIG. 5  depicts a representative example of one manner of disposing multiple, semi-step length facet pairs according to one embodiment of the present invention. A fore-hull non-step partial length facet  512  is situated within a step free fore hull portion and ends at a tapering diminishing inward depth terminus  514 . The non-step partial length facet  512  has a forward greater fraction of increasing depth with rearward progress section  516  that reaches a maximum depth at  518 , and then has a lesser fraction of decreasing depth section  520 . The lengths of the increasing depth section  516  and the decreasing depth section  520  can assume a variety of relatively differing lengths, with an assortment of respective proportions falling within the scope of the present invention, including an increasing section length of any major fraction, i.e. ⅕, ¼, ⅓, ½, ⅔, ¾, or ⅘ of the recess length. The decreasing depth section length will also be similarly variable, though most often the increasing depth section will be of greater length than the decreasing depth section. A middle step partial step length facet  522  is situated within and ends at the rearward terminus of a hull middle step  524 . Either or both of the fore non-step partial length facet  512  and/or the middle step partial step length facet  516  can be configured either individually or both as any of the elongated rectangle first facet plot  312 , the oblique facet  324 , and/or the triangular plan facet  334 , as well others. 
         [0048]    A partial schematic rear view of the transom of a first catamaran embodiment  610  shows a dual faced facet pair disposed on the undersurfaces of the catamaran sponsons  612  on either side of the catamaran tunnel  614 . The dual faced facets are formed with a generally close to vertical first laterally outermost face  616  having a lowermost portion  618  where it meets a hull undersurface outer portion  620 , and a second laterally innermost face  622  that is inclined at a modest upward and outward angle. As shown in  FIG. 6 , the lowermost portion  618  meets the outer hull undersurface  620  of the sponson  612  at a vertical height above that of the inner sponson hull undersurface  624 , though it should be understood that it is within the scope of the invention for these relative heights to be reversed, or even, as well as varying in magnitude. For a modest turn, the water surface may be at a moderate angle  626  which parallels the inclination of the inner sponson hull undersurface  624  and would not substantially engage the first laterally outermost face  616 . A greater degree of turn would heel the vessel over sufficiently so that the water surface angle relative to the vessel would reach or exceed the angle  628  at which point the first laterally outermost face  616  would begin to substantially engage in aiding the vessel to track the turn being executed. As the relative heights of the lowermost portion  618  and the inner sponson hull undersurface  624  are varied in differing embodiments of the present invention, the angle  628  of engagement with the water surface will also vary. 
         [0049]    A partial schematic rear view of the transom of a second catamaran embodiment  710  shows a triple faced facet pair disposed on the undersurfaces of the catamaran sponsons  612  on either side of the catamaran tunnel  614 . The triple faced facet recess is formed by a first laterally innermost face  712 , a second laterally outermost second face  714 , and an intermediate face  716 . The lesser vertical extent of the laterally outermost second face  714  may produce a less substantial turn tracking effect in certain circumstances, but the steeper inclination of the laterally innermost second face  712  which produces a greater cross-sectional area of the recess thereby demarcated, could also in certain circumstances produce a greater turn tracking effect. The variations in these and other such face dimensions, as well as the concomitant variations in the recess cross-sectional areas are encompassed within the scope of the embodiments of the present invention. 
         [0050]    A partial schematic rear view of the transom of a second catamaran embodiment  810  shows a partially arcuate faced facet pair disposed on the undersurfaces of the catamaran sponsons  612  on either side of the catamaran tunnel  614 . The partially arcuate faced facet recess is formed by a first laterally innermost planar face portion  812  which transitions into a second laterally outermost arcuate second face  814  whose lowermost portion  816  meets the outer hull undersurface  620 . In addition to the range of variations in relative heights and inclinations of these faces encompassed by the embodiments of the present invention as described previously in regard to the embodiments depicted in  FIGS. 6 and 7 , also encompassed are variations in a partially arcuate recess cross-sectional area  818  that can also vary in accordance with variations in the second laterally outermost arcuate second face  814  curvature, variations that can include multiple differing curvatures (not shown), as well as variations that include multiple transitions between planar and arcuate curvatures (also not shown), that can have differing curve tracking effects in differing circumstances. 
         [0051]    An elevated perspective partially cut away view of an elongated partially arcuate facet pair embodiment  910  is shown in  FIG. 9 . Among the cardinal features of the elongated partially arcuate facet pair shown, which has much in common with the partially arcuate faced facet pair of  FIG. 8 , is an illustration of the variation in both the recess cross-sectional area and recess height across the longitudinal extent of the elongated partially arcuate facet pair. The rearmost portions of the second laterally outermost arcuate second face  814  and of the first laterally innermost planar face portion  812 , have a substantially greater cross-sectional area and lateral extent, respectively, than do the partially arcuate face foremost section  910  and the first laterally innermost planar face foremost section  912 . As shown in  FIG. 9 , the elongated partially arcuate facet pair have a continuous linear transition from rearward to forward, so that the area and the height of the recesses of the elongated partially arcuate facet pair are continuously increasing when passing from forward to rearward, though in other variants of this embodiment there can be variations in this form of recess height variations. 
         [0052]    A side perspective view of variations in length, height, and cross-sectional area of the elongated partially arcuate facet pair are shown in  FIG. 10 . The elongated partially arcuate facet pair recess  1012  is shown in a partial cross-section with a greater cross-sectional rearward height and area  1014  and a lesser cross-sectional forward height and area  1016 . Among the possible variations in facet length that are encompassed within the scope of the embodiments of the present invention, are those that can reach longitudinal length variations, relative to the vessel resting water line length, of approximately 90%  1018   a , 75%  1018   b , 66⅔%  1018   c , 50%  1018   d , 33⅓%  1018   e , 25%  1018   f , and 10%  1018   g.    
         [0053]    A rear partially schematic and partially perspective view of a transom of a single facet pair embodiment  1110  is shown in  FIG. 11 , which illustrates a number of dimensional and relative dispositional configurations. Most often, unless in an outboard power configuration, the vessel will be powered by either a single inboard engine with a mass concentration I, or powered by a pair of twin inboard engines with mass concentrations II R  and II L . Among the component faces of some embodiments of the present invention are a recess demarcating facet can be included a trio of faces A 1 , B and C, or a pair of faces A 2  and C. In addition, there can be essentially any number of additional faces (not shown), which can vary in angle, length, disposition, topography, and interrelation almost without limit, depending on the circumstances of their use and intended effect. The innermost hull undersurface portions of the hull having no central slot aspect as depicted in  FIG. 11 , situated laterally inward of the facet pair, can have varying deadrise inclinations in differing embodiments such as those of alternative hull portions E 0 , E 1 , and E 2 . The outermost hull undersurface portions D of the hull having no central slot aspect as depicted in  FIG. 11 , situated laterally outward of the facet pair, can likewise have varying deadrise inclinations (not shown) in differing embodiments analogous to the varying deadrise angles of the alternative hull portions E 0 , E 1 , and E 2 . 
         [0054]    The ranges of various dimensional attributes of the constituents and/or interrelations among the constituents of the single facet pair embodiment  1110  include, among others, an absolute vertical reach c 0  of the laterally outermost face C (which is depicted as essentially vertical in  FIG. 11 , but can also have differing inclinations in other embodiments as shown in  FIG. 1 ), and an absolute vertical recess increased reach of the intermediate face B (as well as any additional intermediate faces not shown in  FIG. 11 .) In most embodiments of the present invention, the practical range of the vertical reach c 0  generally ranges in ½ inch increments from a single ½ A inch up to 10 inches; while the practical range of the vertical reach c 1  generally ranges in ½ inch increments from a single negative ½ inch reach up to a positive 10 inches. The laterally innermost face A 1  has an absolute horizontal reach a 1 , and the intermediate face B (as well as any additional intermediate faces not shown in  FIG. 11 ), has an absolute horizontal reach of b. In those embodiments where the outermost face C is not vertically inclined (not shown in  FIG. 11 ), it would also add to the absolute horizontal reach of the recess depicted in  FIG. 11 . The total horizontal reach of the recess is a 2 . For a recess composed of only a vertically inclined face C and face A 2 , a 1  would equal a 2 . In most embodiments of the present invention, the practical range of the total horizontal reach a 2  can vary by almost any gradation even including as small as ½ inch increments, and can span in total anywhere from a few inches up to almost ⅜ of the vessel&#39;s beam, with the total a 2  being divisible among the various other a 1 , b, etc. The horizontal span of d 2  (that side central portion E 0, 1, or 2  of the vessel undersurface inward of the recess), can also vary by almost any gradation, and can have almost any upper bound short of that too large for there to be a sufficient percentage of the vessel beam left over for effective recesses to be present; and a lower bound that can be substantially small, short only of being so limited that it is insufficient to provide any significant support from the water surface, even when on plane, and hence can range down to at the least about 4% of the vessel&#39;s beam. A horizontal span d 3  of that portion D of the vessel hull undersurface outward of the recess is also able to vary by almost any gradation, with a lower bound determined only by hull structural integrity constraints, and an upper bound limited by only the necessity that the left and right faces C are separated by more than 25% of the vessel&#39;s beam. 
         [0055]    Among the potential relative angular orientations of the relationships among the constituents of many possible facet pair embodiments of the present invention, are an angle α 1  of the face A 1  relative to vertical, an angle β of the intermediate face B relative to vertical, an angle γ 1  of the outward hull undersurface portion D relative to vertical, an angle γ 2  of the vessel hull side central portion E 0, 1, or 2  relative to vertical, and an angle θ of the outermost face C relative to horizontal. The size of the gradations of essentially any of these angles can be arbitrarily small, though changes of substantially less than about 5 degrees will be of barely significant effect, so that variations of the angles across the differing embodiments of the present invention can be fairly well described by being considered to range in 5 degree increments across each angle&#39;s full range. Across the breadth of the majority of the embodiments of the present invention, the range of α 1  can be between 5 and 180 degrees; the range of β can be between 0 and 120 degrees, though it will also be limited by that embodiment&#39;s particular value of α 1 ; the range of θ can vary from about 95 degrees down to about 15 degrees; and the angles γ 1  and γ 2  can vary widely depending on the form of construction of the vessel hull as a whole, and are mainly limited by the requirements that the inclinations of the recess faces differ sufficiently from those of the adjacent hull undersurfaces D and E 0, 1, or 2  for the recess to be an effective hull feature, and in the cases where the innermost face A 1  or A 2  meets the outward edge of a central slot aspect, the angle γ 2  can be substantially greater than 90 degrees, ranging upwards almost to 180 degrees. 
         [0056]    In view of the above, it will be seen that the various objects and features of the invention are achieved and other advantageous results obtained. The examples contained herein are merely illustrative and are not intended in a limiting sense.