Abstract:
A boat stabilizer that is attachable to the anti-cavitation plate or other structure of the lower drive unit of a boat motor without permanently modifying the structure of the anti-cavitation plate or other structure is provided. The shape and size of the boat stabilizer causes the stabilizer to effectively harness and control the thrust energy generated by the propeller resulting in improved thrust and fuel efficiency. Due to various features, the drag associated with the boat stabilizer is kept to a minimum. Finally, decals and other decorative elements are integrally embedded into the top surface of the inventive boat stabilizer using in-mold decoration (“IMD”) technology which makes the elements resistant to ultra-violet light, virtually indestructible and highly appealing. A boat motor, a method of attaching a boat stabilizer to a boat motor and a method of molding a boat stabilizer having at least one decorative element integrally embedded in the top surface thereof are also provided.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to boat stabilizers that are attachable to the lower drive unit of a boat motor to provide lift to the stern of the boat and otherwise improve the performance of the boat. The invention also relates to boat motors having a boat stabilizer attached thereto, methods of attaching a boat stabilizer to the lower drive unit of a boat motor and methods of manufacturing boat stabilizers. 
     It is known that the stability, performance, fuel efficiency and safety of certain types of boats (for example, ski boats, bass boats, pontoon boats and the like) can be improved by the addition of an after-market boat stabilizer to the lower drive unit of the boat motor. Such boat stabilizers, often referred to as hydrofoil stabilizers or hydrofoils, are typically designed to fit around the rear of the drive unit over or under the anti-cavitation plate thereof. The boat stabilizers are bolted on to the anti-cavitation plate. Examples are shown by U.S. Pat. Nos. Des. 308,851 (issued Jun. 26, 1990), 5,048,449 (issued Sep. 17, 1991), 5,107,786 (issued Apr. 28, 1992) and Des. 351,129 (issued Oct. 4, 1994), all assigned to the assignee of the present application. 
     A problem inherent in the after-market boat stabilizers used heretofore is that they are bolted directly on to the anti-cavitation plate of the boat motor. This requires that holes (typically 4 or more) be drilled through the anti-cavitation plate. Many boat owners simply do not want to permanently modify the structure of their lower drive units in this manner. Furthermore, drilling the holes in the precise location needed can be difficult. The boat stabilizer needs to be installed in a position that is perpendicular to the longitudinal axis of the engine and in a manner that does not leave any gaps or spaces between the boat stabilizer and the anti-cavitation plate. Gaps and open spaces between the boat stabilizer and anti-cavitation plate can hold water which creates unnecessary drag. In addition, drilling holes in the anti-cavitation plate can void the engine manufacturer&#39;s anti-corrosion protection warranty on new engines. 
     Another problem associated with the boat stabilizers currently available is that the stabilizers do not sufficiently harness the thrust energy generated by rotation of the boat motor propeller. Rotation of the propeller pushes water to the rear, thereby propelling the boat forward. Unfortunately, a great deal of the thrust energy created by the boat motor is lost. Rotation of the propeller imparts a substantially outward, radial force to the water. As the outward, radial force is uniform and symmetric, the associated force vectors tend to cancel out. Only the rearward component of the generated water column, referred to the “thrust cone,” imparts forward thrust to the boat. The diameter of the thrust cone increases with the length of the thrust cone. As a result, some of the water in the thrust cone ultimately is thrown above the surface and into the air, which causes the thrust energy associated therewith to be released and lost. The thrust cone associated with many boats, even when an existing boat stabilizer is utilized, reaches the surface too quickly. For example, boats that create large “rooster tails” are not operating very efficiently. 
     Yet another problem associated with many existing boat stabilizers is stabilizer drag. Drag is the result of friction generated by water flowing over the stabilizer as the stabilizer traverses through the water. The faster the product traverses through the water the greater the drag. Many boat stabilizers on the market do not sufficiently address the problem of drag. 
     Finally, the overall appearance and look of many boat stabilizers rapidly diminishes upon use of the stabilizers. Boat stabilizers are typically molded out of a polymer material by an injection molding process. The molten material is caused to swirl in the mold which results in flow or knit marks in the finished product. In an attempt to improve the aesthetics of the boat stabilizer, many manufacturers place decals (including brand names and logos and/or other decorative elements) on the top surface of the stabilizer. The decals cover up the flow or knit marks on the top surface of the stabilizer. Unfortunately, due to debris in the water and other factors, the decals get beat up and wear out fairly quickly. Even when decals are not used, the top surface of the stabilizer can become worn looking in a relatively short amount of time. 
     By the present invention, a boat stabilizer has been developed that overcomes the aforementioned problems. The inventive boat stabilizer can be attached to the lower drive unit of a boat motor without permanently modifying the structure of the boat motor. The shape and size of the inventive boat stabilizer causes the stabilizer to effectively harness and control the thrust energy generated by the propeller resulting in greatly improved thrust and fuel efficiency. Due to various features, the drag associated with the inventive boat stabilizer is kept to a minimum. Finally, decals and other decorative elements are integrally embedded into the top surface of the inventive boat stabilizer using in-mold decoration (“IMD”) technology which makes the elements resistant to ultraviolet light, virtually indestructible and highly appealing. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a boat stabilizer is provided which overcomes the deficiencies of the prior art described above and has other advantages as well. 
     In one aspect, the invention is a boat stabilizer that is attachable to the lower drive unit of a boat motor (in a manner that allows the stabilizer to function for its intended purpose) without permanently modifying the structure of the lower drive unit. The boat stabilizer comprises a top surface, a bottom surface, a nose portion that includes a front end and a rear end, a tail opposing the nose portion and a main body connecting the nose portion and tail together. The main body includes a wing section for providing lift to the stern of the boat during operation of the boat. Means are associated with the nose portion for attaching said nose portion to the lower drive unit without permanently modifying the structure of the lower drive unit. 
     In a preferred embodiment, the boat stabilizer is attachable to the lower drive unit of a boat motor that includes an anti-cavitation plate above the propeller and a torque tab (or sacrificial anode) attached to the bottom of the anti-cavitation plate by a fastening device that extends through an opening in the anti-cavitation plate. In this embodiment, the nose portion of the boat stabilizer includes an opening that extends through the top and bottom surfaces of the nose portion and can be aligned with the opening in the anti-cavitation plate and receive the fastening device. The means associated with the nose portion for attaching the nose portion to the lower drive unit without permanently modifying the structure of the lower drive unit includes the opening in said nose portion. 
     The nose portion of the inventive boat stabilizer further includes a slot for receiving a portion of the lower drive unit of the boat motor. The means associated with the nose portion for attaching the nose portion to the lower drive unit without permanently modifying the structure of the lower drive unit includes the slot. In a preferred embodiment, the slot extends through the front end toward the rear end of the nose portion of the boat stabilizer and defines a substantially horizontal receptacle for receiving a portion of the lower drive unit (for example, the anti-cavitation plate of the lower drive unit). The slot includes an upper surface and a lower surface that can be clamped together to attach the nose portion to the lower drive unit (for example, the anti-cavitation plate) without permanently modifying the structure of the lower drive unit (for example, the anti-cavitation plate). An aperture extends through the top and bottom surfaces of the nose portion and through the upper and lower surfaces of the slot for receiving a fastening device (for example, a nut and bolt) for clamping the upper and lower surfaces of the slot together. 
     The slot of the nose portion preferably has a depth in the range of from about 5 inches to about 15 inches, more preferably about 8 inches to about 12 inches, and most preferably about 10 inches. The slot of the nose portion preferably has a width in the range of from about 4 inches to about 12 inches, more preferably about 6 inches to about 10 inches, and most preferably about 7 inches. The slot of the nose portion preferably has a thickness in the range of from about 0.125 inches to about 1.25 inches, more preferably about 0.25 inches to about 0.75 inches, and most preferably about 0.5 inches. 
     The inventive boat stabilizer further comprises a pair of opposing wing tips, each of the wing tips being attached to and extending outwardly and downwardly with respect to the main body and having a leading edge and a trailing edge. When the boat stabilizer is installed on the lower drive unit, the wing tips curve down toward the propeller of the boat motor. Compared to some boat stabilizers used heretofore, the width of the inventive boat stabilizer is relatively narrow. However, when installed, the inventive boat stabilizer extends further down and around and further behind the propeller of the boat motor than boat stabilizers used heretofore. In this way, the inventive boat stabilizer maximizes the use of the thrust energy generated by the boat motor and propeller. The thrust energy is kept within the thrust cone. It is in the first few inches beyond the back of the propeller hub where the thrust energy is lost in a conventional outboard or stern drive system. It is in this same area that the inventive boat stabilizer directly addresses and solves the problem. Cavitation and “rooster tailing” are greatly reduced. As a result, increased speed, reduced fuel consumption and a better “holeshot” can be achieved. 
     Two key elements of the inventive boat stabilizer help keep the thrust energy in the thrust cone and thereby allow the stabilizer to make more efficient use of the thrust energy generated by the boat motor and propeller. The first is the length of the stabilizer and the second is the wing tip drop. 
     The inventive boat stabilizer is long enough to counter the effects of cavitation and retain the thrust within the thrust cone, yet not so long that it increases the drag to an unacceptable extent. In one embodiment (designed for use with boat motors having up to 350 HP), the boat stabilizer preferably has an overall length in the range of from about 13.375 inches to about 20.125 inches, more preferably in the range of from about 16.5 inches to about 17.875 inches. In a second embodiment (designed for use with boat motors having up to 75 HP), the boat stabilizer preferably has an overall length in the range of from about 9 inches to about 13.5 inches, more preferably in the range of from about 10.5 inches to about 12 inches. 
     In addition to the length of the boat stabilizer, it is important to get the proper vertical drop of the boat stabilizer wing tips. The effect of the wing tips on the thrust is that they retain the radially vectored thrust within the thrust cone without physically impinging the thrust cone. Accordingly, the wing tips of the inventive stabilizer are configured to extend in a downward position and arranged in a radius above the arc of the propeller. Each of the wing tips of the inventive boat stabilizer preferably extends downwardly with respect to the main body by a distance in the range from about 0.3125 inches to about 7.785 inches. Each of said wing tips preferably extend outwardly with respect to the said main body by a distance in the range of from about 6 to about 9 inches. 
     The inventive boat stabilizer includes many features and elements that function to reduce resistance or drag. For example, the overall shape and dimensions of the stabilizer are designed to reduce drag. Each wing tip is sculpted to include an indentation in the top surface thereof. The indentation is positioned adjacent to the leading edge of the wing tip and helps decrease the resistance of and keep the drag coefficient created by the boat stabilizer to a minimum. Further, the boat stabilizer is integrally formed as a one-piece unit which helps reduce drag. The top surface of the stabilizer includes a recessed section that extends around each of the apertures in the nose portion that receive a fastening devise for clamping the stabilizer on to the anti-cavitation plate. Covers fit within the recessed sections and cover said apertures and any fastening devices therein. This also reduces drag. In addition, the polymer composition used to form the boat stabilizer includes a hydrophilic additive which reduces drag. 
     The inventive boat stabilizer also comprises at least one decorative element that is integrally embedded in the top surface of the boat stabilizer. In a preferred embodiment, the boat stabilizer is molded out of a polymer composition, and the decorative element is embedded in the top surface of the boat stabilizer during the process used to mold the boat stabilizer. For example, the decorative element can be an overlay or logo. IMD technology is utilized. The decorative element is fused into the boat stabilizer during the molding process and creates a seamlessly integrated decorative product and identifier which functions to hide production marks such as flow marks or knit marks. As the decorative element is embedded in the stabilizer during the molding process and fused therewith, it does not wear off during use. It is highly resistant to scratching, scuffing, fading, detergents, hydrocarbon based chemicals and ultraviolet radiation. Additionally, because of the unique in-mold decoration process technology, the final product retains its original properties including shrinkage and flexibility. Further, the in-mold decoration technology allows the incorporation of different protective coatings such as an ultraviolet protective coating. 
     The in-mold decoration process starts with the layering of the film structure with the decorative element. A metallic or metallized material can be used as or as part of the decorative element. Once the layering step is complete, the decorative element is printed and any desired coatings are applied. The printed and coated product is then die cut (trimmed) to the shape of the boat stabilizer or to the particular area where the decorative element is to be placed. The final product is then included in the injection molding process where the printed and coated in-mold decoration film conforms to the texture of the stabilizer. 
     The invention also includes a boat motor comprising an engine, a lower drive unit attached to the engine, and a boat stabilizer that can be removably attached to the lower drive unit to provide lift to the stern of the boat during operation of the boat without permanently modifying the structure of the lower drive unit. The lower drive unit includes a propeller, an anti-cavitation plate positioned above the propeller and a torque tab attached to the bottom surface of the anti-cavitation plate by a torque tab fastening device (for example, a nut and bolt). The boat stabilizer of the boat motor is the inventive boat stabilizer discussed above. 
     The invention also includes a method of removably attaching a boat stabilizer that includes a nose portion, a tail and a main body connecting the nose portion to the tail and including a wing section to the lower drive unit of the boat motor. The method comprises fastening the nose portion of the boat stabilizer to the lower drive unit without permanently modifying the structure of the lower drive unit. In one embodiment, the nose portion of the boat stabilizer is clamped to the anti-cavitation plate of the lower drive unit. 
     The invention also includes a method of attaching a boat stabilizer having nose portion including an opening extending therethrough, a tail and a main body connecting the nose portion and tail together and including a wing section to the anti-cavitation plate of the lower drive unit of the boat motor without permanently modifying the structure of the anti-cavitation plate. 
     The invention also includes a method of molding a boat stabilizer out of a polymer material (for example, a thermoplastic material) with the boat stabilizer having at least one decorative element embedded in the top surface thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a conventional outboard boat motor and associated lower drive unit. 
         FIG. 2  is a perspective view of the inventive boat stabilizer. 
         FIG. 3  is a top view of the boat stabilizer illustrated by  FIG. 2 . 
         FIG. 4  is a rear view of the boat stabilizer illustrated by  FIG. 2 . 
         FIG. 5  is a bottom view of the boat stabilizer illustrated by  FIG. 2 . 
         FIG. 6  is a front view of the boat stabilizer illustrated by  FIG. 2 . 
         FIG. 7  is a side view of the boat stabilizer illustrated by  FIG. 2 . 
         FIG. 8  is a sectional view taken along line  8 - 8  of  FIG. 4 . 
         FIG. 9  is a sectional view taken along line  9 - 9  of  FIG. 3 . 
         FIG. 10  is a top view of another embodiment (a smaller embodiment) of the inventive boat stabilizer. 
         FIG. 11  is a rear view of the boat stabilizer illustrated by  FIG. 10 . 
         FIG. 12  is a side view of the boat stabilizer illustrated by  FIG. 10 . 
         FIGS. 13A through 13G  illustrate the inventive boat motor and the inventive method of attaching a boat stabilizer to a lower drive unit of a boat motor. 
         FIGS. 14A and 14B  illustrate the inventive boat stabilizer (the embodiment illustrated by  FIGS. 2-9 ) as attached to the anti-cavitation plate of a lower drive unit. 
         FIGS. 15A and 15B  illustrate the inventive boat stabilizer (the embodiment shown by  FIGS. 10-12 ) as attached to the anti-cavitation plate of a lower drive unit. 
         FIGS. 16 and 17  illustrate the harnessing and control of the thrust energy achieved by the inventive boat stabilizer. 
         FIGS. 18A through 18C  further illustrate the harnessing and control of the thrust energy achieved by the inventive boat stabilizer. 
         FIGS. 19A and 19B  further illustrate the harnessing and control of the thrust energy achieved by the inventive boat stabilizer. 
         FIGS. 20 through 24  illustrate the inventive method of molding a boat stabilizer out of a polymer material with the boat stabilizer having at least one decorative element integrally embedded in the top surface thereof. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, and particularly to  FIG. 1 , a boat motor suitable for use in connection with the present invention is illustrated and generally designated by the numeral  10 . The boat motor  10  includes an engine  12  (illustrated with the engine cover or housing attached to the engine) and a lower drive unit  14  attached thereto. Although the boat motor  10  shown in  FIG. 1  is an outboard motor, other types of motors including motors having stern drive units can also be used in association with the present invention. For example, with respect to the present invention, the lower drive unit  14  is the same regardless of whether the boat motor  10  is an outboard or a stern drive. 
     As shown by  FIG. 1 , the lower drive unit  14  includes a propeller  16  including a propeller hub  18  and a plurality of blades  20 . A skeg  22  is attached to the lower drive unit  14  and extends below the propeller  16 . An anti-cavitation plate  24  is also attached to the lower drive unit  14  and is disposed in a spaced relationship to and above the propeller  16  to eliminate and reduce certain cavitation effects that would otherwise be created by rotation of the propeller. Virtually every outboard and inboard/outboard motor includes an anti-cavitation plate such as the anti-cavitation plate  24 . 
     A torque tab  26  is attached to the anti-cavitation plate  24 . As used herein and in the appended claims, the term “torque tab” includes torque tabs, sacrificial anodes and similar apparatus mounted to the anti-cavitation plate. The torque tab  26 , which includes a base  28  and a tab  30 , is removably attached to the bottom  32  of the anti-cavitation plate  24  by a fastening device  34 . The fastening device  34  includes a bolt  35  which extends through a corresponding opening  36  in the cavitation plate. The bolt  35  screws directly into the torque tab  26  to fasten the torque tab to the anti-cavitation plate  24 . Alternately, a nut  38  is tightened to the bolt  35  to fasten the torque tab  26  to the anti-cavitation plate  24 . By loosening the fastening device  34 , the torque tab  26  can be rotated right or left with respect to the anti-cavitation plate  24  as necessary to counteract the torque created by rotation of the propeller  16 . 
     Referring now to  FIGS. 2-8 , the inventive boat stabilizer is illustrated and generally designated by the numeral  40 . The boat stabilizer  40  is attachable to a lower drive unit of a boat motor that includes an anti-cavitation plate positioned above a propeller and a torque tab attached to the bottom of the anti-cavitation plate by a torque tab fastening device (for example, a nut and bolt) that extends through a corresponding opening in the anti-cavitation plate; that is, the boat stabilizer  40  is attachable to a lower drive unit of a boat motor such as the lower drive unit  14  shown by  FIG. 1 . The boat stabilizer  40  is attachable to the lower drive unit (in a manner that allows the stabilizer to function for its intended purpose) without permanently modifying the structure of the lower drive unit. For example, the boat stabilizer can be installed without drilling holes in the anti-cavitation plate or other structure of the lower drive unit. 
     The boat stabilizer  40  comprises a top surface  42 , a bottom surface  44 , and a nose portion  46 . The nose portion  46  includes a front end  48 , a rear end  50  and an opening  52  that is disposed between the front and rear ends. The opening  52  extends through the top and bottom surfaces  42  and  44  of the nose portion  46  and can be aligned with the opening in the anti-cavitation plate (e.g., the opening  36  as shown by  FIG. 1 ) to receive a torque tab fastening device (e.g., the bolt  35  as shown by  FIG. 1 ). This allows the nose portion  46  to be attached to the anti-cavitation plate by the torque tab fastening device (e.g., the nut  38  and the bolt  35  as shown by  FIG. 1 ). 
     The nose portion further includes a slot  56  extending through the front end  48  toward said rear end  50  and defining a substantially horizontal receptacle  60  for receiving the anti-cavitation plate. The slot  56  includes an upper surface  62  and a lower surface  64  that can be clamped together to hold the nose portion  46  onto the anti-cavitation plate. As used herein and in the appended claims, the designations “horizontal” and “vertical” apply to the orientation of the components of the invention as such components are illustrated in the accompanying drawings. 
     The boat stabilizer  40  further includes a tail  66  opposing the nose portion  46  and a main body  68  connecting the nose portion and the tail together. The main body  68  includes a wing section  70  for providing lift to the stern of the boat during operation of the boat. 
     The opening  52  in the nose portion  46  of the boat stabilizer  40  is elongated and has a longitudinal axis  72  that is substantially parallel to the longitudinal axis  74  of the boat stabilizer. As shown, the opening  52  has an oval cross-sectional shape. The opening  50  can have other cross-sectional shapes as well, such as a rectangular cross-sectional shape. 
     As best shown by  FIG. 5 , the bottom surface  44  of the boat stabilizer  40  includes a recessed area  76  around the opening  52  in the nose portion  46  for receiving the base of the torque tab of the lower drive unit (such as the base  28  as shown in  FIG. 1 ). For example, the base of the torque tab (such as the base  28  as shown in  FIG. 1 ) fits snugly within the recessed area  76 . 
     The nose portion  46  of the boat stabilizer  40  further includes an upper notch  80  for receiving a portion of the lower drive unit. Upper notch  80  extends from the front end  48  of the nose portion  46  to the rear end  50  of the nose portion and through the top surface  42  of the boat stabilizer  40 . The upper notch  80  has a longitudinal axis  82  that is substantially parallel to the longitudinal axis  74  of the boat stabilizer and includes a back wall  84  and opposing side walls  86  and  88 . 
     The nose portion  46  of the boat stabilizer  40  further includes a lower notch  90  for receiving a portion of the lower drive unit. The lower notch  90  extends from the front end  48  of the nose portion  46  toward the rear end  50  of the nose portion and through the bottom surface  44  of the boat stabilizer  40 . The lower notch  90  has a longitudinal axis  92  that is substantially parallel to the longitudinal axis  74  of the boat stabilizer  40  and includes a back wall  94  and a pair of opposing side walls  96  and  98 . 
     The slot  56  has an open front end  100  adjacent to the front end  48  of the nose portion  46  and a rear end  102 . A pair of opposing side walls  104  and  106  extend from the open front end  100  to the rear end  102 . The open front end  100  of the slot  156  has a width  108  that is greater than the width of the rear end  102  of the slot  56  and greater than the width of the anti-cavitation plate. 
     A pair of apertures  110  extend through the top surface  42  and bottom surface  44  of the nose portion  46  and through the upper surface  62  and lower surface  64  of the slot  56 . Each aperture  110  is disposed adjacent to the open front end  100  and a side wall ( 104  or  106 ) of the slot  56 . The apertures  110  receive a fastening device (for example a bolt) for clamping the upper surface  62  and lower surface  64  of the slot  56  together and attaching the nose portion  46  to the anti-cavitation plate without permanently modifying the structure of the anti-cavitation plate. If a bolt is used, a nut is tightened to the bolt to achieve the clamping mechanism. 
     The boat stabilizer  40  further comprises a pair of opposing wing tips  120 , each of the wing tips being attached to and extending outwardly and downwardly with respect to the main body  68  and having a leading edge  124  and a trailing edge  126 . Each of the wing tips  120  includes an indentation  128  in the top surface  42  thereof. The indentation  128  is positioned adjacent to the leading edge  124  of the wing tip  120 . By sculpting the top surface  42  of the wing tips along the leading edges thereof; i.e., by including the indentations  128 , the drag resistance created by the boat stabilizer  40  is reduced and the drag coefficient corresponding to the boat stabilizer is kept to a minimum. 
     The boat stabilizer  40  further comprises a plurality of decorative elements  130  that are integrally embedded in the top surface  42  of the boat stabilizer. The decorative elements  130  include a domed logo plate  132 , a chrome overlay  134  surrounding the logo plate, a stainless steel overlay  136  covering a large portion of the top surface  42  of the boat stabilizer  40 , a pair of red flame stripes  138  and a carbon fiber overlay  140  extending over each of the wing tips  120 . 
     The boat stabilizer  40  is preferably formed in an injection mold out of a polymer composition (e.g., a thermoplastic composition such as polypropylene). As explained below, utilizing IMD technology, the decorative elements  130  are integrally embedded in the top surface  42  of the boat stabilizer  40  during the molding process. The decorative elements  130  are highly resistant to scratching, fading, detergents, hydrocarbon based chemicals and ultraviolet radiation. 
     The top surface  42  of the boat stabilizer  40  further comprises a pair of recessed sections  144  extending around the apertures  110 . A pair of covers  146  fit within the recessed sections  144  to cover the apertures  110  and any fastening device therein. The covers  146  decrease the resistance created by the boat stabilizer  40 . 
     The top surface of the boat stabilizer  40  further includes a plurality of longitudinal recessed sections  148  that are positioned side by side in the top surface and extend from the tail  56  toward the nose portion  46  of the boat stabilizer. The recessed sections  148  also help reduce drag. Except for the covers  146 , the boat stabilizer is integrally formed as a one piece unit. 
     The embodiment of the boat stabilizer shown by  FIGS. 1-9  is most useful in connection with outboard (stern drive) motors up to 350 horsepower. The specific embodiment of the stabilizer  40  shown in  FIGS. 1-9  has an overall length of approximately 17⅞ inches and an overall width of approximately 18 inches. The width of the front end  48  of the nose portion  46  and hence the approximate width of the open front end  100  of the slot  156  is approximately 7 3/16 inches. The slot  56  has a depth of about 10 inches, and a thickness of about 0.5 inches. 
       FIGS. 10-12  illustrate a smaller embodiment of the boat stabilizer  40 . Except for its size, the embodiment of the boat stabilizer  40  illustrated by  FIGS. 10-12  is essentially the same as the body of the inventive boat stabilizer illustrated by  FIGS. 1-9 . The specific embodiment of the stabilizer  40  illustrated by  FIGS. 10-12  has an overall length of approximately 12 inches and an overall width of approximately 12 inches. The width of the front end  48  of the nose portion  46  and hence the approximate width of the open front end  100  of the slot  56  is about 6⅛ inches. 
     When the boat stabilizer  40  is installed on the lower drive unit, the wing tips  120  curve down toward the propeller of the boat motor. Compared to some boat stabilizers used heretofore, the overall width of the inventive boat stabilizer  40  (both the embodiment shown by  FIGS. 1-9  and the embodiment shown by  FIGS. 10-12 ) is relatively narrow. However, when installed, the inventive boat stabilizer  40  extends further down and around and further behind the propeller of the boat motor than boat stabilizers used heretofore. In this way, the inventive boat stabilizer maximizes the use of the thrust energy generated by the boat motor and propeller. 
     In the embodiment shown by  FIGS. 1-9  (designed for use with boat motors having up to 350 HP), the boat stabilizer  40  preferably has an overall length in the range of from about 13.375 inches to about 20.125 inches, more preferably in the range of from about 16.5 inches to about 17.875 inches. In the embodiment shown by  FIGS. 10-12  (designed for use with boat motors having up to 75 HP), the boat stabilizer preferably has an overall length in the range of from about 9 inches to about 13.5 inches, more preferably in the range of from about 10.5 inches to about 12 inches. 
     Each of said wing tips of the inventive boat stabilizer preferably extends downwardly with respect to the main body by a distance in the range from about 0.3125 inches to about 7.785 inches. Each of said wing tips preferably extend outwardly with respect to the said main body by a distance in the range of from about 6 to about 9 inches. 
     As best illustrated by  FIG. 1 ,  FIGS. 13A through 13G ,  FIGS. 14A and 14B  and  FIGS. 15A and 15B , the invention also includes a boat motor  10 . The boat motor  10  includes an engine  12  (illustrated with the engine cover or housing attached to the engine), a lower drive unit  14  attached to the engine, and a boat stabilizer  40  (not shown in all of the figures) removably attached to the lower drive unit to provide lift to the stern of the boat during operation of the boat without permanently modifying the structure of the lower drive unit. Although the boat motor  10  shown in the drawings is an outboard motor, other types of motors including motors with stern drive units can also be used in association with the present invention. For example, with respect to the present invention, the lower drive unit  14  is the same regardless of whether the boat motor  10  is an outboard or a stern drive motor. 
     The lower drive unit  14  includes a propeller  16  including a propeller hub  18  and a plurality of blades  20 . A skeg  22  is attached to the lower drive unit  14  and extends below the propeller  16 . An anti-cavitation plate  24  is also attached to the lower drive unit  14  and is disposed in a spaced relationship to and above the propeller  16  to eliminate and reduce certain cavitation effects that would otherwise be created by rotation of the propeller. Virtually every outboard and inboard/outboard motor includes an anti-cavitation plate such as the anti-cavitation plate  24 . 
     A torque tab  26  is attached to the anti-cavitation plate  24 . The torque tab  26 , which includes a base  28  and a tab  30 , is removably attached to the bottom  32  of the anti-cavitation plate  24  by a fastening device  34 . The fastening device  34  includes a bolt  35  which extends through a corresponding opening  36  in the cavitation plate. The bolt  35  screws directly into the torque tab  26 . Alternately, a nut  38  is tightened to the bolt  35  to fasten the torque tab  26  to the anti-cavitation plate  24 . By loosening the fastening device  34 , the torque tab  26  can be rotated right or left with respect to the anti-cavitation plate  24  as necessary to counteract the torque created by rotation of the propeller  16 . 
     The boat stabilizer  40  is the inventive boat stabilizer  40  described above. The opening  52  in the nose portion  46  of the boat stabilizer  42  is aligned with the opening  36  in the anti-cavitation plate  24  and receives the torque tab fastening device  34  (namely, the bolt  35 ) whereby the nose portion can be attached to the anti-cavitation plate by the torque tab fastening device. Specifically, the nut  38  is tightened to the bolt  35  to fasten the nose portion  46  to the anti-cavitation plate  24 . The receptacle  60  defined by the slot  56  receives the anti-cavitation plate  24 . The upper and lower surfaces  62  and  64  of the slot  56  are clamped together to hold the nose portion  146  onto the anti-cavitation plate  24 . Specifically, a bolt  160  is extended through each of the apertures  110 , and a nut  162  is tightened onto each of the bolts to clamp the upper and lower surfaces  62  and  64  together. 
     Referring now to  FIGS. 13A through 13G , the method by which the inventive boat stabilizer  40  is attached to the lower drive unit  14  of the boat motor  10  without permanently modifying the structure of the anti-cavitation plate  24  or otherwise modifying the structure of the lower drive unit  14  or boat motor is illustrated and described. 
       FIG. 13A  illustrates a lower drive unit  14  prior to installation of the boat stabilizer  40  thereon. As best shown by  FIGS. 13B and 13E , the retaining bolt  35  that retains the torque tab  26  to the bottom  32  of the anti-cavitation plate  64  is located. The retaining bolt  35  removed from the corresponding opening  36  in the anti-cavitation plate  24 . The torque tab  26  is then removed from the anti-cavitation plate  34 . 
     Next, as shown by  FIGS. 13B and 13C , the nose portion  46  of the boat stabilizer  40  is slid onto the anti-cavitation plate  24 . The boat stabilizer  40  is pushed forward onto the anti-cavitation plate  24  until it stops (i.e., until the back wall  84  of the upper notch  80  and/or back wall  94  of the lower notch  90  abut against the lower drive unit  14 ). The base  28  of the torque tab  26  is then inserted into the recessed area  76  on the bottom surface  44  of the boat stabilizer  40  over the opening  52 . The bolt  35  is then extended through the opening  52  in the nose portion, through the opening  36  in the anti-cavitation plate  24  and through the torque tab  126 . The nut  38  is then retighten to the bolt  35 . 
     Next, a bolt  160  is extended through each of the apertures  110 , and a nut  164  is tightened to each of the bolts  160  to clamp the upper surface  62  and lower surface  64  of the nose portion  46  together with the anti-cavitation plate  24  sandwiched therebetween. This method securely attaches the inventive boat stabilizer  40  to the lower drive unit  14  without permanently modifying the structure of the anti-cavitation plate  24  or otherwise permanently modifying the structure of the lower drive unit  14 . The torque tab  26  and fastening device  34  securely attach the boat stabilizer  40  to the lower drive unit  14 . The clamping mechanism provided by the upper and lower surfaces  162  and  164  of the slot  56  further secure the attachment. 
     Referring now to  FIG. 16 , the thrust cone  200  is represented in relation to boat stabilizer  40 , and propeller  16 . Thrust cone  200  is shown aft of boat stabilizer  40 . The wing tips  120  of the boat stabilizer  40  redirect the thrust from propeller  16  and contain potential lost energy within the thrust cone  200 .  FIG. 17  is a rear-view of the boat stabilizer  40  and the propeller  16 , and illustrates the radial flow of the thrust as it is contained within the thrust cone  200  and the expansion of the thrust cone as it departs the boat stabilizer  40 . The wing tips  120  contain the thrust within the thrust cone  200 . 
     Referring now to  FIGS. 18A-18C , the thrust cone  200  is shown with and without the boat stabilizer  40  attached to the boat motor. As shown by  FIG. 18A , without a stabilizer  40 , a large rooster tail  202  is generated immediately around the thrust cone  200 . The primary direction of travel for the thrust cone  200  is shown by thrust vector  204 . Lost thrust due to the rooster tail  202  is shown by lost thrust vector  206 .  FIG. 18B  illustrates a flat stabilizer  216  attached to the boat motor. Again, a rooster tail  202  is generated immediately around the thrust cone  200 , except in this case the effect is further away from the propeller  16 . The primary direction of travel for the thrust cone  200  is shown by thrust vector  204 . Lost thrust vector  206  again depicts the lost thrust due to cavitation and rooster tails above the surface of the water.  FIG. 18C  illustrates the thrust cone  200  when inventive boat stabilizer  40  is employed. A significantly longer thrust cone  200  and thrust vector  204  are achieved. The thrust cone  200  is shown remaining below the surface of the water thereby retaining the maximum energy for the thrust along thrust vector  204 .  FIGS. 19A and 19B  further illustrated the thrust cone  200  with and without boat stabilizer  40 .  FIG. 19A  illustrates a cone of lost energy  218  above the surface of the water while the remaining, effective part of the thrust cone  200  is shown to be below the surface of the water. The cone of lost energy  218  directly subtracts from the available energy of the thrust cone  200  as the boat has forward motion. The center line  220  of thrust cone  200  is shown to be nearly parallel with the surface of the water.  FIG. 19B  illustrates how the inventive boat stabilizer  40  redirects the energy from the propeller  16  downwardly and into the thrust cone  200 . In this illustration, the cone of lost energy  218  in  FIG. 19A  is now contained by the boat stabilizer  40  and redirected along the thrust cone  200  center line  214 . Center line  214  is now angled downwardly and away from the surface of the water because the boat stabilizer  40  has deflected the previously wasted energy into positive energy thereby increasing the rate of forward motion for the same power input. 
     The inventive boat stabilizer  40  is preferably prepared from a thermoplastic composition that comprises a thermoplastic polymer and a hydrophilic additive dispersed throughout the polymer. The hydrophilic additive comprises from about 0.01% to about 5.0% by weight of the stabilizer. A boat stabilizer prepared from such a polymeric composition experiences less hydrodynamic drag than a stabilizer lacking the hydrophilic additive. The preferred thermoplastic composition is described in U.S. patent application Ser. No. 10/749,147 (filed Dec. 30, 2003), which is assigned to the assignee of the present application and is hereby incorporated by reference herein. 
     The invention also includes a method of molding the boat stabilizer  40  of a polymer material with the boat stabilizer having at least one decorative element  130  embedded in the top surface  42  thereof. 
     Referring now to  FIGS. 20-24 , the method comprises the steps of:
         a. placing a completed in-mold decoration (“IMD”) film  250  in a mold  252  used to form the boat stabilizer  40  adjacent to a surface  254  of the mold  252  that forms the top surface  42  of the boat stabilizer;   b. after step a, injecting the polymer material into the mold  252 ; and   c. after step b, allowing the polymer material to harden in the mold  252  to form a boat stabilizer  40  having a decorative element  130  integrally embedded in the surface thereof.