Abstract:
A surfboard having a hull, a multi-function fin and multi-function fin receiving box system. This invention incorporates the use of a variety of fins, fin bases including multi-tab, rectangular and positioning inserts. Receiving box and locator inserts are optionally configured so that the fin may be adjustable positioned and secured in a three-dimensional configuration. The fins positioning may include fore and aft, cant angel and angel of attack positioning. The fin positioning may be adjusted through recessed wedge or other shaped receiving voids and insert elements positioned in and around the structural wall areas of the receiving box. The interior wall surfaces of the fin-securing cavity accommodate the positioning of the fins base attachment and aligning structures and are constructed with various extended, receiving, positioning, supporting and securing features.

Description:
SUMMARY OF THE INVENTION  
       [0001]     This patent application claims the benefit of an earlier provisional patent filing dated Nov. 26, 2004 with patent application Ser. No. 60/631,120 and having the same inventorship.  
       BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to surfboards and particularly surfboards with removable and optionally adjustable fins that provide the user options for fin and fin base choices and adjustments of the fin placement distances, angle of attack and splay or cant angles. The design and manufacturer of removable surfboard fins and the fin box receivers chosen by either the surfboard manufacturer or the customer has had problems for some time now. This is due to a variety of reasons and the consequences were significant when the choice of the fin and box receiver was made. The fin and receiver box would accommodate primarily only that one fin manufacturer&#39;s products for additional or replacement fin products. The surfer was limited to that original fin manufacture and only that fin manufacture due to the fin base or attachment details involving the receiver box. The individual can need a wide range of fin placements and products due to the wave and water conditions found around the world. More specifically, a surfer would select a surfboard with a specific fin placement set-up and that was unchangeable. Depending upon the waves style, sizes, and the ocean conditions of the waves the fin placement and configuration angels can make a significant difference in the board&#39;s performance. Removable surfboard fin manufacturers set a predetermined fin angle or cant angle and the fore and aft fixed position for the fin. This invention optionally provides for the receiving box to adapt and accept a variety of fins through the combinations of void receiving spaces and inserts and to optionally provide for variable fin movement in the fore and aft, in the cant angle and in the fins leading edge and or trailing edge to moved up or down. The multi-function nature of this invention in the wide variety of fins combined with the wide variety of adjustments that can be chosen and fixed are of significant advantage over the existing fin boxes, the fins and the fin adjustment. This invention pertains to a surfboard fin and receiving fin box attachment device, the optional installation methods of universal fin and fin box and their respective forces during their dynamic use. This invention incorporates the use of a variety of fin bases including multi-tab and rectangular bases for attachment and adjustment with locators, supports, receivers and securing elements. The multi-fin use base receives, adjusts for multi-axis three-dimensional movement, secures and releases both multi-tab base and a single rectangular fin base configurations. This three dimensional movement consists one spatial and two rotational movements. The fore and aft movements are spatial and the cant angle and leading edge up and down are rotational. The invention includes a surfboard fin attachment box having a generally rectangular fin placement or receiving cavity. This cavity is housed inside a outer perimeter structural walled support housing with a upper deck surface and alternatively can incorporate a recessed continuous or non-continuous trough incorporated into a horizontally extending lower deck flange surface and structure located below the perimeter edge of the rectangular fin placement cavity upper deck surface. The fins and fin boxes of this invention may have a variety of shapes that can include cylindrical, oval or rectangular lower deck flange and perimeter outline. The optional lower deck flange deck extends outwardly from the trough forming the outermost perimeter outline. The surfboard fin box attachment device is installed in the surfboard foam blank or a hollow surfboard structure either prior to the surface composite skinning step or in the composite lay-up or lamination process and maybe installed after the curing of the skins.  
         [0003]     In the prior art, such as U.S. Pat. No. 6,916,220 a replaceable fin or fins are attached and adjusted on and in the boards by a variety mechanisms which provide the positioning securing and removal of the fin directed at the adjustments of the cant angle of the fin. In one fin system the replaceable fins are tabbed and positioned into round plugs with securing screws in a surfboard.  
         [0004]     In the prior art a replaceable fin or fins attached and adjusted on and in the boards are presented by a variety mechanisms which provide the positioning securing and removal of the fin directed at the adjustments of various positions of the fin. The present invention distinguishes over this art with a series of various inventive structures forming extended, receiving, supporting, positioning and securing features.  
       DESCRIPTION OF THE RELATED ART  
       [0005]     In the preferred embodiment of this invention the surfboard fins and fin box attachment device of this invention can provide universality or multiple dissimilar fin design attachment compatibility for the placement, adjustability for movement, securing and removal of the surfboard fins. The two preferred fin base configurations are both a non-canted multi-tab base and a canted single rectangular fin base configuration. The interior wall surfaces of the fin-securing cavity accommodate the positioning of the fins base attachment structures and are constructed with various extended, receiving, supporting and securing features. This box wall and cavity structure incorporates the individual and unique fin base physical structural features and requirements and provides for the securing or affixing and or joining of them. This fin adjusting and securing is achieved through a combination of fin base elements fitting into or adjoining to interior cavities, affixing to or attaching to interior support shaped parts and being secured with one or more and or in combination with embedded securing screws, interior affixing or securing attaching devices such as pins. The surfboard fin attachment box can incorporate an outer ledge or deck wall surface located at the perimeter edge of the rectangular fin placement cavity for both the structural support of the fin and provide the attachment surface or platform and edge for the surfboards bottom composite materials to secure to by joining to this platform surface. The surfboard fin box attachment device can provide for the forward and backward, cant and up and down adjustment movements and the securing of the surfboard fin in the final position. Surfboard fins can be manufactured with a variety of fin base shapes and configurations. These can include the fin base either having a fin base with no base canting or with fin base canting. This fin adjustability can be accomplished for a non-canted fin base through a continuous diagonal or wedge shaped recessed canted cavity area in the interior sidewall of the fin box cavity. Two wedge shape cavities can be provided for non-canted multi-tab fins. This allows the straight fin and fin base to be supported by surrounding the base of the multi-tabs from the side and from below and inside the cavity of the fin box full length. The adjustability is accomplished through a continuous or noncontinousley diagonal canted cavity in the wall of the fin box for the multi-tab fin. The optional movement for the canted rectangular fin base can also be accommodated with a longer rectangular cavity length than that of the fins base. The surfboard fin box attachment device is installed in the surfboard either prior to the surface composite skinning step or after a lay-up or lamination process has cured. The fin box can be reinforced with a denser or more rigid material both inside the board and or outside on or in the surface composite skin. The fin box may be combined with a denser foam or structural reinforcing block for added structural strength resisting the dynamic forces of the fins. The installation of the fin box can incorporate the addition of a polymer stabilized, dye cut material reinforcing the outer surface or outer composite skin. The combined composite covers the box deck and extends outwardly to transfer the dynamic loads of the fin into the surfboard. The fin box device of this invention can be installed in all stages of the surfboards construction including the molding operation of a molded solid core or a molded hollow surfboard. The surfboard fins that are compatible with and incorporated into this invention that are not presently covered by prior patents are considered to be incorporated into the patentable elements and inclusive of the art of this invention and as such would be covered by this patent.  
         [0006]     An alternative embodiment of this invention incorporates a surfboard fin attachment box with perimeter shape outlines of varying dimension and contours that vary to provide the interior fitting requirements of the specific fins and their bases.  
         [0007]     An alternative embodiment of this invention incorporates into the surfboard fin attachment box the manufacturing of the box using both a thermo-plastic for the main box receiving cavity and a semi-flexible composite structural re-enforcing material within the thermo-plastic molded part during the molding manufacturing process. This element of the invention combines a cured thermo-plastic box cavity with a semi-cured but secured portion of the composite in the box cavity and the remaining portion of the uncured flexible composite extending outwardly from the box structure. The extended portion of the uncured composite is designed to lay flat on the bottom surface of the surfboard during the box installation process and is cured with a polymer material either during installation or in the lamination or lay-up process  
         [0008]     An alternative embodiment of this invention incorporates into the surfboard fin attachment box the structural and physical extension of the boxes lower structure for attachment to the inside of the upper deck surface of the surfboard.  
         [0009]     An alternative embodiment of this invention incorporates into the surfboard fin attachment box the structural and physical extension of lateral gusset structures for stabilizing the structures forces.  
         [0010]     An alternative embodiment of this invention incorporates into the surfboard fin attachment box the structural receiving or attachments points combined with the structural linking of two or more of the boxes with one another internally or inside the surfboard for the stabilizing or controlled movement of the boxes and fins. This optionally can be combined with the linking of two or more side box and fin systems to a somewhat centrally located main stabilizing element. This combination of box, fin and central stabilizing structural system transfers and balances the forces of the rider and the surfboard by providing a structural skeleton linking the fins, fin boxes and surfboard to the dynamic forces and movements of the wave and rider.  
         [0011]     In one of the alternative embodiments larger and potentially soft covered foil fins may be used by the novice surfer. The larger foil fin can stabilize the rider for the learning process. This process is vastly accelerated due to the increased ease of learning to balance, stabilize and steer or turn from the wider, forward portion of the surfboard. The increased capability to balance, stabilize and control the board from the wider portion of the board is a part of the reasons for the accelerated learning process. As the surfer progresses his position on the board will move further back on the board there by increasing the turning power of the board.  
         [0012]     The movable foil can be used with or without additional fixed foils to fine-tune the board&#39;s performance to meet individual surfer&#39;s preferences or variable wave characteristics. Controllable foil allows the surfer to turn and control direction and maneuverability on the wave with the pitch or rotational action of the foil or foils by the rear foot, which in turn controls the pitch the board in any maneuver. The more increased the pivot or rotational attitude change of the foil by the foot movement the greater the effect on the surfboard. This control is in sharp contrast to that of traditional fixed foil fin surfboards  
         [0013]     Multiple fin base configurations may be optionally positioned in the receiver box and secured for attachment and adjustment with locators, supports, positioners, receivers and securing elements.  
       BRIEF SUMMARY OF THE INVENTION  
       [0014]     This invention provides for the receiving box to adapt and accept a variety of fins through the combinations of optional secondary void receiving spaces provided fore in the molding process of the main cavity of the fin receiving box. This feature is combined with a variety of inserts and the invention optionally provides for variable fin movement in the fore and aft, in the cant angle and in the fins leading edge and or trailing edge to moved up or down of the adjustment of the angels of attack of the fin and any of it appendages.  
         [0015]     The present invention provides multi-functional surfboard fin boxes, multi-functional fins, and combines them with the, three dimensional fin movement that enables a surfer to adapt the surfboard as best suited to his personal, wave and sea conditions. The present invention eliminates the conventional inconvenient need of purchasing, maintaining, and transporting a variety of surfboards to suit various surf conditions. The methods and apparatus of the present invention customize a board to a variety of variable performance needs and requirements of the surfer.  
         [0016]     In one embodiment of the invention, a surfboard includes the board, the fin, a receiving cavity in the fin box in the surfboard, and a means for positioning the fin fore and aft, in cant and in the up and down angle of attack of the fin relative to the angle of the surfboard. The fin is positioned in the receiving cavity of the fin box, and extends from the surfboard lower planning surface with the three-dimensional configurations selected and fixed. The receiving cavity in the fin box when combined with the needed inserts is configured so that the fin is adjustable in a variety of fore and aft, cant, and up and down positions. An example could be the receiving cavity in the fin box may be configured optionally with both sidewall void secondary receiving cavity to allow the fin base to pivot in the secondary receiving cavity in the fin box. When the fin is positioned in a desired fore and aft, cant, and up or down position the inserts and or the securing screws position and affix the fin in the required three-dimensional position  
         [0017]     In one embodiment of the present invention, a fin base may be secured in the optionally provided side wall void secondary receiving cavity or cavities to allow the fin base to pivot and thereby adjusting the fins cant angle by the fin base placement in the secondary receiving cavity of the fin box. The fin may then be securied by either a screw system or pin system. In this example, the fastener could include a threaded hole configured such that the screw secures the base of the fin either directly engaging the receiving cavity within the fin base and thereby locking the insert in the main box cavity. Altematively, the insert may include engagement structures for locking the fin in the main box cavity.  
         [0018]     One of the features of the invention is that the surfer may reposition the fin at alternative three-dimensional positions either in the fin-receiving box and/or in the fin-receiving base if desired. To achieve this repositioning in the fin receiving box, the screw is backed out to release the fin base and the insert, the fin is then fixed at new position angels, and the fastener is actuated to secure the fin. The adjustable fin incorporating the fin tang and fin tang receiving cavity may also achieve the repositioning in the fin receiving cavity, the screw is backed out to release the fin tang from the base, the fin is then fixed at new position angels, and the fastener is actuated to secure the fin. The side fins may selectively be positioned in mirror symmetry or asymmetrically. The side fin may be selected as the same or different from one another.  
         [0019]     One of the features of the invention is that the installer in the installation process may position the fin box at alternative height positions either in the finished or pre finished surfboard during installation and then sand down the elevated deck to meet the need deck height surface of the board and the fin receiving box.  
         [0020]     In one embodiment of the present invention, a fin base box may be secured in the foam prior to the skinning of the surfboard. The upper deck provides a partial removable raised area protruding above the plane of the surfboard bottom prior to its height reduction thru sanding during the construction installation. This feature provides a flush finished surface with the bottom surfboard surface while retaining the laminating fiberglass material right up to the edge of the fin base-receiving cavity. The lower deck provides the attachment plane for the fiberglass to adhere to plus the added feature of reducing the glass removed in the sanding step found in other surfboard fin box systems. Additionally a continuous polymer reservoir has been positioned at the intersection point of the lower decks horizontal plane and the vertical wall extending up from the trough to the upper deck sand able deck. This reservoir polymer trough provides the wetting required from below of the fiberglass to reduce air and maintain the fiberglass&#39;s adhered integrity around the fin base opening.  
         [0021]     The following detailed description is in conjunction with the attached drawings. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0022]      FIG. 1  is an isometric view of a center receiving fin box attachment device according to an embodiment of the invention, illustrating a number of the securing thru holes, the upper and lower decks, the continuous trough, the fin base cavity and main structural body;  
         [0023]      FIG. 2  is an isometric view of a center receiving fin box attachment devices according to an embodiment of the invention, illustrating a number of the securing through holes, the upper and lower decks, the continuous trough, the fin base cavity and rear securing pin.  
         [0024]      FIG. 3  is a top view of a center receiving fin box attachment devices according to an embodiment of the invention, illustrating a number of the securing thru holes, the upper and lower decks, the continuous trough, the main fin base cavity and rear securing pin.  
         [0025]      FIG. 4  is a side view of a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a center fin box with an upper and lower deck and a main receiving body.  
         [0026]      FIG. 5 . is an end view of a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with structural side gussets.  
         [0027]      FIG. 6 . is an isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with secondary sidewall receiving cavities.  
         [0028]      FIG. 7 . is a top view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with a number of the securing thru holes and rectangular main receiving fin base cavity and the continuous trough.  
         [0029]      FIG. 8 . is a side view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box with an upper and lower deck and a main receiving body.  
         [0030]      FIG. 9 . is a end view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box with an upper and lower deck and a main receiving body.  
         [0031]      FIG. 10 . is an isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with an extended secondary sidewall receiving cavities.  
         [0032]      FIG. 11 . is a top view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with a number of the securing thru holes and a extended rectangular main receiving fin base cavity and the continuous trough.  
         [0033]      FIG. 12 . is an isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with a number of the securing thru holes installed in the extended rectangular main receiving fin base cavity and the continuous trough and a fin configured with a screw receiving and securing area on the fin base.  
         [0034]      FIG. 13 . is a isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with a number of the securing thru holes installed in the extended rectangular main receiving fin base cavity and the continuous trough and a fin configured with a screw receiving and securing area mounted at the front of the extended fin receiving base.  
         [0035]      FIG. 14 . is a isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box insert that is configured with extended secondary side wall receiving cavities and screw receiving slots.  
         [0036]      FIG. 15 . is a isometric view of a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a center fin box insert that is configured with extended secondary side wall receiving cavities containing screw receiving slots and side wall reinforcements.  
         [0037]      FIG. 16 . is an isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box insert that is configured with secondary sidewall receiving cavities and screw receiving slots.  
         [0038]      FIG. 17 . is a isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box insert that is configured with secondary side wall receiving cavities and screw receiving holes.  
         [0039]      FIG. 18 . is a isometric view of a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a center fin box insert that is configured with secondary side wall receiving cavities containing screw receiving holes and side wall reinforcements.  
         [0040]      FIG. 19 . is an isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box insert that is configured with a secondary sidewall receiving cavities and screw receiving holes.  
         [0041]      FIG. 20 . is an isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with secondary sidewall receiving cavities.  
         [0042]      FIG. 21 . is an isometric view of a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a center fin box.  
         [0043]      FIG. 22 . is an isometric view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box insert that is configured with secondary sidewall receiving cavities.  
         [0044]      FIG. 23 . is a end view of a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with secondary side wall receiving cavities with structural supporting gussets.  
         [0045]      FIG. 24 . is an end view of a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a center fin box with structural supporting gussets.  
         [0046]      FIG. 25 . is a end view of a side receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box insert that is configured with secondary side wall receiving cavities with structural supporting gussets.  
         [0047]      FIG. 26 . is a side view of a side fin and fin base according to an embodiment of the invention particularly illustrating a side fin and receiving fin base that is configured with a fin extension tang and fin base receiving slot and an exterior securing screw area.  
         [0048]      FIG. 27 . is a end view of a side fin and fin base according to an embodiment of the invention particularly illustrating a side fin and receiving fin base that is configured with a fin extension tang and a receiving fin base with a variable degree cant angle.  
         [0049]      FIG. 28 . is a end view of a side fin and fin base according to an embodiment of the invention particularly illustrating a side fin and receiving fin base that is configured with a fin extension tang and a receiving fin base with a zero degree cant angle.  
         [0050]      FIG. 29  is a top view of a side receiving fin box attachment devices according to an embodiment of the invention, illustrating a securing thru hole, the upper and lower decks, the continuous trough and the fin base cavity and rear securing pin. the lower deck contains air and fluid release ports.  
         [0051]      FIG. 30  is a bottom view of a side receiving fin box attachment devices according to an embodiment of the invention, illustrating a the fin base cavity body configured with structural supporting gussets and lower deck containing air and fluid release ports.  
         [0052]      FIG. 31  is an isometric view of a tapered insert. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0053]     Referring to the drawings in more detail, a multi-function center fin-receiving box of the present invention is illustrated in  FIG. 1 . Securing thru holes  1  provide opposing securing and positioning screw attachment points to the exterior screw area  17  of the main fin base structure  6 , providing a secured and removable fin positioned in the fin base cavity  2  and supported by the main structural body  6 , the upper deck  10  provides a partial removable raised area protruding above the plane of the surfboard bottom prior to it&#39;s height reduction thru sanding during the construction installation, the lower deck  3  has positioned at the intersection point of its horizontal plane and the vertical wall  5  a raised structure extending up from the trough  4  to the upper deck  10 , a continuous reservoir trough  4 .  FIG. 2  illustrates the additional optional securing pin  8  feature.  FIGS. 3,4  and  5  show the approximate relative relationships of size and scale of the optional securing pin  8 . In  FIG. 4  and  FIG. 5  the upper deck area  10  in relation to the lower deck area  3  and the box&#39;s main body  6 . In  FIG. 5  the optional structural stabilizing side gussets  7  are shown and the sidewall connecting the upper deck to the lower deck  3 . In accordance with the optional principles of the present invention, at least one of the fins may be adjustable by the user; the user may adjust and fix positions by releasing one or more of the securing screws from one of the fins  32  ( FIG.12 ) then reposition and secure the fin at additional positions and angles as needed. By comparison to existing fin systems which have limited or no movement the present invention provides optional fore and aft adjustment, a fin side out and back cant angle adjustment and an up and down angle of attack angle adjustment, the optional adjustable-fin features of the invention allows a user to adjust the fin or fins as desired in multi-dimensional axis&#39;s either symmetrically or asymmetrically.  
         [0054]     The elements presented for utilization in this description, are equally applicable to other water vessels, such as knee boards, body boards, water skis, wake boards, sailboards and other wave, motor, paddle or self-propelled watercraft vehicles.  
         [0055]     An optional side receiving fin box illustrated in  FIG. 6 , may include one or more secondary sidewall receiving cavities  9 . According to multi-function embodiments of the present invention, the receiving cavities shown in  FIG. 10  and  FIG. 11  each receiving fin box may be optionally provided with one or more extended secondary side wall cavities  20  and with an extended rectangular main receiving fin cavity  11 . Illustrated in  FIG. 12  is the pre-positioned adjustable fin  32  with a rectangular fin base  14  and extended rectangular main receiving cavity  11 . When positioned in the extended rectangular main receiving cavity  11  the securing screws are extended down and into the screw receiving area  17 . Each of the two preferred fin base types, the dual tab and the rectangular  14  may be adjustable positioned in the extended receiving fin cavity  11  and the main extended fin base  33  with or without inserts.  FIG. 13  illustrates the fin  32  positioned in the extended rectangular main receiving cavity  11  in a full forward position. The dual tab fin base system may be similarly fore and aft adjusted, positioned and fixed in the fin-receiving box. Both fin base systems may be adjusted in one or more of the three-dimensional positioning options provide for in this invention.  
         [0056]     With additional reference to  FIGS. 10 and 12  and according to an exemplary embodiment of the invention, each side box and each dual tab based fin may utilize an optionally provided and correctly sized adaptive insert.  FIG. 10  and  FIG. 12  may utilize a fin securing, positioning and or adjusting insert element as illustrated in  FIGS. 14 and 16 . The insert in  FIG. 15  provides the center fin positioning and securing features including the screw receiving slots  24 . This or additional inserts may be used individually or in combinations such as that illustrated in  FIG. 31  to achieve the one spatial and/or two rotational three-dimensional positions optional provided for in the present invention. The insert illustrated in  FIG. 31  can be placed in the main rectangular fin receiving cavity or a reduced version can be placed in the forward or rear secondary sidewall receiving cavity areas  20  to achieve a increased or decreased angle of attack of the fin or any of it&#39;s appendages. Additionally the  FIG. 31  insert may be used in conjunction with  FIG. 1  or an extended version.  
         [0057]     With additional reference to  FIG. 6  and according to an exemplary embodiment of the invention, each side box and each dual tab fin based fin may utilize the optionally provided and correctly sized insert.  FIG. 6  may utilize a fin securing, positioning and or adjusting insert element as illustrated in  FIGS. 17 and 19  with  FIG. 18  illustrates the insert providing the center fin positioning and securing features including the screw receiving holes. This or additional inserts may be used individually, or in combinations such as that illustrated in  FIG. 31  to achieve the one spatial and/or two rotational three-dimensional positions optional provided for in the present invention. The insert illustrated in  FIG. 31  can be placed in the main rectangular fin receiving cavity or a reduced version can be placed in the forward or rear secondary sidewall receiving cavity areas to achieve a increased or decreased angle of attack of the fin or any of it&#39;s appendages. Additionally the  FIG. 31  insert may be used in conjunction with  FIG. 1  or and extended version.  
         [0058]     With additional reference to  FIGS. 14, 15 ,  16 ,  17 ,  18  and  19  according to an exemplary embodiment of the invention, each insert and each dual tab fin based fin securing system may utilize the optional side wall reinforced material  22  and  25  for providing both the very thin thickness and structural requirements of the insert.  FIGS. 15 and 12  illustrate securing features  23  that allow both screws and pins to position and affix the fin and optionally the insert and the fin  32 .  
         [0059]      FIGS. 20, 21  and  22  illustrate a right and left side and a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with secondary sidewall receiving cavities.  FIGS. 23, 24  and  25  illustrate a right and left side and a center receiving fin box attachment device according to an embodiment of the invention particularly illustrating a side fin box that is configured with secondary side wall receiving cavities with structural supporting gussets  7  and may include air and hydraulic venting ports  33  as illustrated in  FIGS. 29 and 30  to assist in the installation methods of the invention. These and other modifications are also within the scope of the present invention.  
         [0060]     Referring to the drawings in more detail, a multi-function side and or center fin of the present invention are illustrated in  FIGS. 26, 27  and  28 .  FIG. 26  illustrates the provision for the securing and positioning screws (not shown) that may be engaged into the exterior screw area  17  of the fin base  14 , providing a secured, movable and or removable fin positioned in the fin base cavity of this invention and the fin  32  is optionally configured with a fin extension tang  16  for affixing or removable placing into the internal receiving tang slot cavity  34  (outline indicated by the broken lines). With additional reference to  FIGS. 26, 27  and  28  according to an exemplary embodiment of the invention, the multi-functional based elements of fin securing system may utilize an optional side securing screw (not shown) and or pin hole  35  and slot  36  feature illustrated in  FIG. 26 . The securing features  35  and  36  allow both screws and pins to adjust the fins fore and aft and the angle of attack in the fin base  14  position and affix the upper fin element of the fin  32  into the fin base cavity  34  of the fin base  14 .  FIG. 27 . is an end view of a side fin and fin base according to an embodiment of the invention particularly illustrating a side fin tang  29  and receiving fin base internal slot  28  that is configured with a fin extension tang  29  with a variable degree cant angle option resulting in a variable adjustment of the fins finished installed cant angle. This variable fin cant angle is manufactured into the fin base tang  29  for installation prior to the time of use.  FIG. 28 . is a end view of a side fin and fin base according to an embodiment of the invention particularly illustrating a side fin tang  31  and receiving fin base internal slot  30  that is configured with a fin extension tang  16  with a non-variable degree cant angle option of 0 degrees resulting in a finished installed cant angle of the zero degrees for the fins. This non-variable fin cant angle is manufactured into the fin base tang  29  for installation prior to the time of use. The variable cant angel may also be provided for in the molded fin base part, the receiving cavity being off set for the cant angel, replacing the need for the cant angel in the fin tang. With additional references to  FIGS. 26, 27  and  28  rather than configuring the screw and pin of the invention with a screw-and-tapped-hole arrangement, the fin and fin base may be configured as a snap-in fastening system. Accordingly, the present invention is not limited to details and elements precisely as shown and described above but by the scope of the appended claims.