Abstract:
A sponson attachment for an airboat allows the airboat to increase its safety and stability very quickly. A method for attaching a sponson to an airboat hull includes attaching first and second flexible tethers to a side of the sponson. The method also includes removably securing the first flexible tether to an exterior of the airboat hull adjacent a gunnel, and removably securing the second flexible tether below the first flexible tether on the exterior of the hull.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority from U.S. Provisional Application No. 62/252,106, filed on Nov. 6, 2015, the disclosure of which is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    Air-propelled watercrafts, or airboats, use air-propulsion to propel flat-bottom hulled boats through waterways. Traditionally, the boats include a rear mounted propeller that extends above the hull of the boat. Such watercrafts are relatively compact, allowing them to maneuver through brush, reeds, or other low-water conditions. However, these airboats have drawbacks. For example, in the case of open water conditions, and in particular in windy conditions where currents or waves may be significant, traditional airboats become unstable and could capsize. This is partly due to the fact that airboats tend to utilize hulls with low sides and have comparatively tall propeller assemblies, making the boats top heavy. Additionally, there exist other conditions in which it is unsafe to operate an airboat, such as in inclement weather conditions. 
         [0003]    For these and other reasons, improvements are desired. 
       SUMMARY 
       [0004]    The present disclosure relates generally to a sponson attachment for an airboat hull to improve the safety and stability of the airboat. In one possible configuration, and by non-limiting example, the sponsons are inflatable and removably attached at the sides of an airboat hull. 
         [0005]    In a first aspect of the present disclosure, a method for attaching a sponson to an airboat hull is disclosed. The method includes attaching a first and second flexible tether to a side of the sponson. The method also includes removably securing the first flexible tether to an exterior of the airboat hull adjacent a gunnel. The method also includes removably securing the second flexible tether below the first flexible tether on the exterior of the hull. 
         [0006]    In a second aspect of the present disclosure, an airboat hull sponson retrofit kit is disclosed. The kit includes an inflatable sponson that has a first and second tether attached to a side thereof. Each tether has an attachment cylinder secured to an end. The kit also includes a first tether attachment for attaching to an airboat hull. The first tether attachment includes a channel that is configured to receive the attachment cylinder of the first tether. The kit also includes a second tether attachment for attaching to the airboat hull, and the second tether attachment also includes a channel configured to receive the attachment cylinder of the second tether. 
         [0007]    A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The following drawings are illustrative of particular embodiments of the present disclosure and therefore do not limit the scope of the present disclosure. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the present disclosure will hereinafter be described in conjunction with the appended drawings, wherein like numerals denote like elements. 
           [0009]      FIG. 1  illustrates a perspective view of an airboat according to one embodiment of the present disclosure; 
           [0010]      FIG. 2  illustrates a perspective side view of the airboat of  FIG. 1 ; 
           [0011]      FIG. 3  illustrates a schematic side view of a sponson attached to a side of the airboat of  FIG. 1 ; 
           [0012]      FIG. 4  illustrates a schematic side view of a sponson and corresponding attachment mechanisms attached to a side of the airboat of  FIG. 1 ; 
           [0013]      FIG. 5  illustrates a top view of an airboat according to one embodiment of the present disclosure; 
           [0014]      FIG. 6  illustrates a perspective side view of the airboat of  FIG. 5 ; 
           [0015]      FIG. 7  illustrates a schematic rear view of the airboat of  FIG. 5 ; and 
           [0016]      FIG. 8  illustrates a schematic rear view of the airboat of  FIG. 5  with sponson holders in an alternative arrangement. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Various embodiments will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims. 
         [0018]    The removably attachable sponson kit disclosed herein has several advantages. The kit allows an existing airboat to be retrofitted to include a pair of floatable sponsons secured to the hull of the airboat. The sponsons provide the airboat with additional buoyancy, which increases the safety of the airboat. Additionally, the sponsons provide the airboat with additional stability, allowing the airboat to safely traverse deeper and rougher water while decreasing the likelihood of the boat capsizing and/or submerging if capsized. 
         [0019]    An airboat  100  is shown in  FIG. 1 . The airboat  100  includes a hull  102 , a propeller assembly  104 , and a pair of removable sponsons  106   a,    106   b.  The airboat  100  is configured to transport cargo and people across a variety of different waterways under a variety of different conditions. 
         [0020]    The hull  102  can be configured in a variety of ways to haul a variety of different cargo loads. In some embodiments, the hull can include a rider deck with a plurality of seats. In other embodiments, the hull can be configured to haul cargo. In the depicted embodiments, the hull is a flat-bottomed hull. Further, the hull  102  is constructed of metal or other hard, resilient material. In some embodiments, the hull  102  is constructed of aluminum. The hull  102  includes a front  108 , a rear  110 , a left side  112 , and a right side  114 . As shown, the front  108  of the hull  102  includes an upward sloping bottom  116 . At the rear  110  of the hull  102 , the propeller assembly  104  is attached. At both the left and right sides  112 ,  114 , removable sponsons  106  are mounted to the hull  102 . 
         [0021]    The propeller assembly  104  is shown schematically in  FIG. 1 . The propeller assembly  104  includes a support structure  118  for housing a propeller  120 . The propeller  120  is powered by a motor (not shown). The propeller  120 , when driven by the motor, propels the airboat  100  through the water. More specifically, the propeller  120  generates a rearward column of air that propels the airboat  100  in a forward direction. A rudder (not shown) can be included, as is known in the art, to steer the airboat  100  in an operator-selectable direction. 
         [0022]    In the embodiment shown, the airboat  100  includes the first sponson  106   a  and the second sponson  106   b  attached at the sides  112 ,  114  of the hull  102 . Specifically, the first and second sponsons  106   a,    106   b  are inflatable and removably attached to the hull  102 . The sponsons  106   a,    106   b  provide stability and flotation to the airboat  100  and enable the transport of loads or personnel. In some alternative embodiments, the sponsons may be rigid. In the depicted embodiment, the sponsons  106   a,    106   b  follow the shape of the sides  112 ,  114  of the hull and are at least partially curved near the front  108  of the hull. For example, the sponsons can be substantially cylindrical, and be tapered at a front end (bow end) and/or a back end (stern end). In the example shown, the sponsons  106   a,    106   b  are tapered at a front end, e.g., toward a bow of the airboat hull. Additionally, the sponsons can be of complementary shapes to be located along the hull, e.g., being mirror images of one another. 
         [0023]    Other sponson shapes are also possible to accommodate a variety of differently shaped hulls. For example, the sponsons could be formed from a unitary tube, and form a U-shaped outer hull surrounding a front and both sides  112 ,  114  of the airboat  100 . In such an arrangement a portion of the sponsons  106   a - 106   b  that spans across the front of the airboat may be raised relative to the side portions to reduce any possible drag caused by that portion. In example embodiments, the sponsons  106   a,    106   b  can, when mounted to the hull, be located at a height above a water line of the airboat hull when the airboat is loaded to a predetermined degree (e.g., based on an average load, or based on a maximum load), thereby reducing drag caused by the sponsons  106   a,    106   b  during normal operation of the airboat  100 . 
         [0024]    The sponsons  106   a,    106   b  are preferably scratch and abrasion resistant, and thus, may endure for long periods in rough water environments, including swift water, white water, open sea, ice, snow, and shallow water mixed with rocks and/or vegetation. For example, the airboat  100  is designed to travel in high waves and/or shallow water. The sponsons  106   a,    106   b  may also be unaffected by gas, oil, and diesel that may seep from the motor or from other external or internal sources. Due to their inflatable characteristics, the sponsons  106   a,    106   b  act as bumpers and fenders and rebound off of objects (i.e., rocks, ice, other watercrafts, or the like) that may exist in the trajectory of the airboat  100  to which they are attached. In some embodiments, the sponsons  106   a,    106   b  are made from polyurethane and are bullet-proof to 9 mm ammunition. In other embodiments, the sponsons  106   a,    106   b  may be made from alternate materials and may be bullet-proof to varying degrees. 
         [0025]    The sponsons  106   a,    106   b  may also be equipped with one or more baffles, or separable chambers, within the sponsons  106   a,    106   b.  The baffles promote floatation and prevent or mitigate the effects of vibrations, which are increased in rough water conditions. In other words, the baffles promote stability of the sponsons  106   a,    106   b,  and ensure that a single puncture of a sponson would not immediately compromise flotation. 
         [0026]      FIG. 2  shows an isometric view of a portion of the airboat  100 , specifically the left side  112  of the hull  102  and the attached sponson  106   a.  Positioning of the sponson  106   b  at the right side  114  of the hull  102  is substantially similar to the positioning of the sponson  106   a,  and therefore not shown. As shown, the sponson  106   a  is attached to the hull  102  adjacent a gunnel  122  of the hull  102 . By attaching the sponson  106   a  next to the gunnel  122  of the hull  102 , less of the sponson is likely to drag in the water during operation of the airboat  100 . This allows the airboat to operate with less drag in the water, allowing it to travel at high speeds and be more maneuverable. However, because the sponson  106   a  is mounted on the side  112  of the hull, the sponson  106   a  still provides support and stability to the airboat  100  during times when it becomes unstable. Additionally, the sponson  106   a  provides a barrier for crashing waves so as to help prevent water from entering the interior of the airboat  100 . 
         [0027]      FIGS. 3-4  show schematic views of the attachment used to removably attach the sponsons  106   a,    106   b  to the hull  102 . Again, only the left side  112  is shown; however, positioning and attachment of the sponson  106   b  at the right side  114  of the hull  102  is substantially similar. As shown, the sponson  106   a  includes a first tether  124 , and a second tether  126  each attached at a side  128  (shown in  FIG. 2 ) of the sponson  106   a.  The tethers  124 ,  126  are then attached to upper and lower attachment mechanisms  128 ,  130  respectfully. The upper and lower attachment mechanisms  128 ,  130  are secured to hull  102  and are configured to hold the sponson  106   a  securely against the side  112  of the hull  102 . As shown, each upper and lower attachment mechanism  128 ,  130  includes a channel  132 ,  134 . 
         [0028]    The first and second tethers  124 ,  126  are secured to the side  128  of the sponson  106   a  and are flexible. In some embodiments, the tethers are adhered to the sponson. In still other embodiments, they are stitched to the sponson  106   a.  In other embodiments, the tethers are manufactured from the same material as the sponsons  106   a,    106   b.  Further, the tethers  124 ,  126  each include interfacing portions  136 ,  138  at ends  140 ,  142 . In the depicted embodiment, the interfacing portion  136 ,  138  are cylinders that are configured to slide within the channels  132 ,  134  of the upper and lower attachment mechanisms  128 ,  130 . The interfacing portions  136 ,  138  can be sized and shaped in variety of different ways so long as they match the size and shape of the channels  132  and  134 . 
         [0029]    The upper and lower attachment mechanisms  128 ,  130  can be constructed of metal or other resilient material. The upper attachment mechanism  128  is secured adjacent the gunnel  122  of the side  112 . In the depicted embodiment, the upper attachment mechanism  128  is secured under a lip  144  of the gunnel  122 . In some embodiments, the lip  144  can be secured to the hull  102  during the fitting of the sponson  106   a.  The lower attachment mechanism  130  is also secured at the exterior of side  112 . 
         [0030]    In one embodiment, the sponsons  106   a,    106   b  and their respective tethers  124 ,  126 , along with upper and lower attachment mechanisms  128 ,  130  for each side  112 ,  114  can be distributed as a retro-fit kit for airboats. This allows a user to removably attach the sponsons  106   a,    106   b  to the airboat  100  when desired, allowing the user freedom to customize their particular airboat for specific applications. 
         [0031]      FIGS. 5-8  depict an airboat according to another embodiment of the present disclosure.  FIG. 5  shows a schematic top view of an airboat  200 . The airboat  200  includes a main hull  202 , a propeller assembly  204 , and a pair of sponsons holders  206   a,    206   b.  Like the airboat  100  described above, the airboat  200  is configured to transport cargo and people across a variety of different waterways under a variety of different conditions. Additionally, the airboat  200  can be used as a rescue boat and provides the user improved stability and safety over traditional airboats. 
         [0032]    The interior of main hull  202  can be configured in a variety of ways to haul a variety of different cargo loads. As depicted, the main hull  202  includes a bench  207  that is positioned longitudinally with respect to the main hull  202 . In some embodiments, the main hull  202  can include a rider deck with a plurality of seats. In other embodiments, the main hull  202  can be configured to haul cargo. In the depicted embodiments, the main hull  202  is a flat-bottomed hull and is constructed of metal or other hard, resilient material. In some embodiments, the main hull  202  is constructed of aluminum. Like the hull  102  described above, the main hull  202  includes a front  208 , a rear  210 , a left side  212 , and a right side  214 . As shown, the front  208  of the main hull  202  includes an upward sloping bottom. At the rear  210  of the main hull  202 , the propeller assembly  204  is attached. At both the left and right sides  212 ,  214 , the sponson holders  206   a,    206   b  are attached to the main hull  202 . In some embodiments, the sponson holders  206   a,    206   b  may be rigidly attached the main hull  202 . In other embodiments, the sponson holders  206   a,    206   b  may be integral with the main hull  202 . 
         [0033]    The sponson holders  206   a,    206   b  are configured to hold inflatable sponsons (shown in  FIGS. 6-8 ) so as to provide additional floatation and stability to the airboat  200 . The sponson holders  206   a,    206   b  can hold sponsons similar to the sponsons  106   a,    106   b  described above. In some embodiments, sponsons may be permanently attached to the sponson holders  206   a,    206   b.  In other embodiments, sponsons may be removably attached to the sponson holders  206   a,    206   b,  for example using the tethers as described above in connection with  FIGS. 1-4 . As shown, the sponson holders  206   a,    206   b  are attached at the sides of the main hull  202  and are constructed as cages. The sponson holders  206   a,    206   b  are rounded and rigid so as to accept the inflatable sponsons. In some embodiments, the sponson holders  206   a,    206   b  are constructed of metal or similarly rigid material. As shown, the sponson holders include a plurality of rails  216  to contain the sponsons within the sponson holders  206   a,    206   b.    
         [0034]      FIG. 6  shows a left side view of a portion of the airboat  200 . As shown, the sponson holder  206   a  surrounds a sponson  209  so as to mount the sponson  209  to the main hull  202 . Additionally, the sponson holder  206   a  is positioned so as to position the sponson  209  above a bottom  211  of the main hull  202 . This allows the main hull  202  to ride in the water while the sponson  209  floats on top of the water, which creates less drag for the airboat  200 . The right side  214  of the airboat  200  is substantially similar to the left side  212 , and therefore not shown. 
         [0035]      FIG. 7  shows a back schematic view of the airboat  200 . As shown, the sponson holders  206   a,    206   b  have a half moon cross-section. This shape allows the sponson holders  206   a,    206   b  to provide rigidity to the sponsons that are secured inside the holders  206   a,    206   b.  As shown, the sponson holders  206   a,    206   b  each have an open side  218   a,    218   b  that faces the bottom  211  of the main hull  202 , e.g., is convex in shape. 
         [0036]      FIG. 8  shows an alternative arrangement for the sponson holders  206   a,    206   b  on the airboat. In the depicted embodiment, the open sides  218   a,    218   b  of the sponson holders  206   a,    206   b  face away from the bottom  211  of the main hull  202 . Such positioning allows the sponsons  209  to sit and be secured in the sponson holders  206   a,    206   b,  e.g., being concave in shape. 
         [0037]    Referring to  FIGS. 1-8  generally, it is recognized that the watercraft disclosed herein have a number of advantages over existing airboats or other watercraft. In particular, the improvements disclosed herein allow for increased safety for airboats, especially when using such airboats as rescue boats. The sponsons allow for improved maneuverability, while also allowing for improved buoyancy and handling in open water and adverse weather conditions. 
         [0038]    The various embodiments described above are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.