Abstract:
A stable fishing raft that is easily transportable to the water without a trailer and has a deck large enough to easily and securely carry fishing gear. The deck and bottom are flat, and the sides are perpendicular to the deck and bottom. The deck is connected to the bottom at the bow and stern with a circular arc. The core of the raft is a buoyant foam, preferably polyurethane, and covered in a water-resistant resin, preferably polyethylene. The raft is steerable and propelled by paddle or trolling motor that attaches to a removable motor mount. In a preferred embodiment the raft has a recessed accessory track and a series of recessed rings on the deck to receive the bottom edge of a bucket and hold it in place as a seat. Rafts can be joined together with couplers.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation-in-part of co-pending U.S. patent application Ser. No. 15/424,864 filed Feb. 5, 2017, which is a continuation-in-part of U.S. patent application Ser. No. 14/281,959 filed May 20, 2014, which claims the benefit of U.S. Provisional Patent Application 61/859,699 filed Jul. 29, 2013. 
     
    
     FIELD OF INVENTION 
       [0002]    This invention relates generally to rafts and more particularly to steerable rafts that are stable in the water when stationary and can support people and equipment. 
       BACKGROUND 
       [0003]    Fishing is one of the most popular outdoor recreational activities in the United States with over 45 million Americans taking at least one fishing trip a year. In concept the gear necessary for fishing is simple: a fishing pole with a hook and maybe some bait. In reality people need a lot more gear. A day of fishing from the bank still requires the fishing pole, a hook and bait, but it also needs a tackle box for lures, replacement hooks, sinkers, and tools for fixing the tackle to the line. A bow fisherman needs his bow, arrows, and extra points and line. A fisherman may also want a chair or stool so he can sit on the bank and stay dry, as opposed to standing all day or sitting in the mud. The fisherman may also want one or more extra poles, and a creel or cooler to hold the caught fish. Hauling all the gear from one fishing spot to another takes so much time and effort that a fisherman stays in one spot all day, regardless of whether the fish are biting there. 
         [0004]    Beyond bank fishing, many fishermen would prefer to fish from the water. Typically they use boats, such as small skiffs, pontoon barges, or larger open boats. One problem with those boats is that they are so large that they have to be towed on a trailer, which takes fishing from the water to an unreachable expense for many people, not to mention the inconvenience of getting the boat in and out of the water and its upkeep. Further, boats, canoes, kayaks and personal watercraft are intended as primarily moving vessels and are relatively unstable while sitting stationary in the water. For example, some people fish from canoes, but canoes are wildly unstable when stationary unless the fisherman is seated in the boat, which can make it difficult to cast, to shoot an arrow, or change positions in the canoe. 
         [0005]    It would be desirable to have a watercraft for fishing which is stable when stationary, which can be conveniently transported to and from the water, which will hold all the gear wanted for a good day of fishing, and yet be relatively inexpensive. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention is a stable fishing raft that is easily transportable to the water without a trailer and has a deck large enough to easily and securely carry fishing gear. The deck and bottom are flat, and the sides are perpendicular to the deck and bottom. The deck is connected to the bottom at the bow and stern with a circular arc. The core of the raft is a rigid buoyant foam, preferably closed-celled polyurethane and covered in a water-resistant resin. If the shell is rotational molded or blow molded then filled with foam, the coating is preferably polyethylene. If the foam is shaped first then coated, the coating is preferably polyurea. The raft is steerable and propelled by paddle or motor that attaches to a removable motor mount. In a preferred embodiment the raft has a recessed accessory track, a safety line, and a series of recessed rings on the deck to receive the bottom edge of a bucket and hold it in place as a seat. Rafts can be joined together with couplers. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a top view of one embodiment of the raft. 
           [0008]      FIG. 2  is a bottom view of one embodiment of the raft. 
           [0009]      FIG. 3  is a rear view of one embodiment of the raft. 
           [0010]      FIG. 4  is a front view of one embodiment of the raft. 
           [0011]      FIG. 5  is a left side view of one embodiment of the raft. 
           [0012]      FIG. 6  is a right side view of one embodiment of the raft. 
           [0013]      FIG. 7  is a top rear perspective view of one embodiment of the raft. 
           [0014]      FIG. 8  is a bottom rear perspective view of one embodiment of the raft. 
           [0015]      FIG. 9  is a top front perspective view of one embodiment of the raft. 
           [0016]      FIG. 10  is a bottom front perspective view of one embodiment of the raft. 
           [0017]      FIG. 11A  illustrates the curvature of the bow and stern of the raft. 
           [0018]      FIG. 11B  is a cutaway view along line A-A of  FIG. 11A  illustrating the right angles of the deck, sides, and bottom. 
           [0019]      FIG. 11C  illustrates the curvature of an alternative embodiment of the bow and stern of the raft. 
           [0020]      FIG. 12  is a top rear perspective of another embodiment of the raft. 
           [0021]      FIG. 13  is a bottom rear perspective of another embodiment of the raft. 
           [0022]      FIG. 14  is a perspective view of a coupler. 
           [0023]      FIG. 15  is a close-up partial view of a coupler connecting two rafts. 
           [0024]      FIG. 16  is a rear view of two coupled rafts. 
           [0025]      FIG. 17  is a perspective view of a removable motor mount. 
           [0026]      FIG. 18  illustrates a trolling motor attached to a motor mount installed in a raft. 
           [0027]      FIG. 19  is a top perspective view of the raft illustrating a bucket seated in a recess. 
           [0028]      FIG. 20  is a bottom perspective view of a bucket seat. 
           [0029]      FIG. 21A  is a top perspective view of the raft showing the raised lip. 
           [0030]      FIG. 21B  is a close-up view of the raised lip. 
           [0031]      FIG. 22  shows a perspective view of an accessory track above the accessory recess. 
           [0032]      FIGS. 23A-D  illustrate rear views of prior art watercraft compared to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0033]    This invention is a raft  10  having a core of a buoyant foam material. The raft  10  has a rectangular flat deck  11  and a rectangular flat bottom  12 . See  FIGS. 1 and 2 , respectively. A flat port side  13  is perpendicular to the deck  11  and perpendicular to the bottom  12 . A flat starboard side  15 , shown in  FIG. 6 . and in part in  FIG. 18 , is perpendicular to the deck  11  and perpendicular to the bottom  12 . See  FIGS. 3, 4, and 11B . A curved bow  16  connects the front  14  of the deck  11  to the bottom  12  and a curved stern  17  connects the rear  19  of the deck  11  to the bottom  12 . See  FIGS. 5-10, 12 and 13 . As used herein, flat means a surface without curvature such that if viewed on edge it would appear to be a straight line. A flat surface may be smooth or not smooth, where smooth means a surface without marked lumps or indentations. 
         [0034]    The present rafts&#39; primary use is as a stationary platform, in contrast to boats, canoes, kayaks and personal watercraft, which are intended as primarily moving vessels. Stationary, as used herein, means not moving much in relation to a point on the shore, although the raft may pitch, yaw and roll a bit while stationary due to any current and the surface characteristic of the water. The present raft provides a stable platform for activities that occur primarily in one location, such as fishing in a certain spot for many minutes or hours. The shape of the present raft makes it more stable while stationary than watercraft with sloped or curved sides. The shape in combination with a buoyant foam core make the present raft particularly stable when stationary. 
         [0035]    Due to the improved stability of the raft, it is even stable when being propelled slowly, such as by paddle or with a trolling motor at low power. The raft can be steered hands free by the user simply shifting his weight from one side of the raft to the other side. In this way a user can steer the raft much like a skateboarder steers a skateboard. 
         [0036]    Sloped or curve sides reduce drag, which is desirable for moving vessels. However, sloped or curved sides also decreases stability when the vessel isn&#39;t moving. The greater the curve, the less drag and less stability. Drag is not a concern for rafts most of the time, because rafts move a relatively small portion of the time they are on the water. Instead, a raft permits a user to have a stable surface while remaining stationary. Of course, a raft has to travel some distance to reach a desired fishing spot, so too much drag is not desirable because it makes the raft unwieldy as a moving vessel. The curve of the bow and stern on the present raft is set to minimize drag while traveling forward or backward. The straight sides are set to maximize stability when the raft is stationary. The present raft provides the perfect balance of maximum stability while stationary with acceptable drag getting to a desired location. 
         [0037]      FIG. 23A-D  shows the rear view of the present raft in comparison to rear views of prior-art watercraft of various shapes. “D” indicates areas of reduced displacement on prior art watercraft, relative to the present raft  10  having a flat bottom  12  and perpendicular sides  13  and  15 . With the present raft  10 , if traveling sideways or crabbing—that is, the raft is travelling perpendicular to its lengthwise axis—water is forced away from the deck, increasing stability. If the present raft rolls to the port or starboard side the ratio of the average depth of material submerged to the water displaced remains constant, thus countering the rolling motion. That is, one side increases in depth while the other side decreases in depth. The side that increases in depth however also experiences an increase in buoyant force. The straight sides of the present raft—vertical when the raft is at horizontal rest—retard water from coming on the deck, which would reduce buoyancy. Lateral opposing forces will be more quickly cancelled by the rectangular shape of the present raft and less likely to force water onto the deck. 
         [0038]    In one embodiment the bow and stern have the same curvature. In a preferred embodiment the curvature is an arc of a circle having a radius r that is 42.7% larger than the thickness d of the raft: r=1.427d. See  FIG. 11A . The center of the circle sits above the horizontal line H of the deck  11  at a height of h, with an arc length l an angle theta  8 . In the preferred embodiment the bow and stern curvature is an arc of a circle having a radius of 8.5625 inches and the center of the circle is spaced above the deck at 2.5625 inches, h=2.5625. See  FIG. 11A . The resultant arc length l is about 10.8 inches with angle θ of about 72°. 
         [0039]    In another embodiment, the bow and the stern have the same curvature as shown in  FIG. 11A  plus an additional radius of curvature on the port and starboard sides, as indicated in  FIG. 11C , to form a rounded deck edge, as shown in  FIGS. 1-4 and 12 . As shown in  FIG. 11C , for a raft that has a deck of 48×96×6 inches, radius r=8.5625 inches, the distance from the center of the circle to the end of the raft a is about 8.1 inches, b is about 3.0 inches and c is about 5.1 inches. 
         [0040]    The deck  11  and the bottom  12  are rectangles of equal width. The deck  11  is longer than the bottom  12  due to the shortening of the bottom  12  to accommodate the curvature of the bow  16  and stern  17 . In one embodiment the width of the deck is half the length. In a preferred embodiment the deck is 48 inches wide and 96 inches long, the bottom is 48 inches wide and 80 inches long, and the raft is 6 inches thick. The preferred embodiment of the raft is sized to fit in the bed of a pick-up truck. 
         [0041]    The raft has a foam core. Suitable materials include extruded polystyrene foam, expanding marine polyurethane foam, aerogel, Airloy™, expanded polystyrene foam, spray foam, closed-cell-foam, polyisocyanurate, cross linked PE foam, plastic foam, polymers, and carbon. In one embodiment the foam is a closed cell, pourable foam, which resists the absorption of water. In a preferred embodiment the foam is closed-cell polyurethane having a density of about 1-2 lb/ft 3 . The raft may be formed by molding, rotational molding, blow-molding, or cutting blocks or sheets of foam into the desired shape. The edges may be sharp corners but are typically slightly rounded, which serves to prevent mechanical damage and to help a molded raft release from its mold. 
         [0042]    A coating is applied to the core to give it a harder outer shell to help prevent mechanical damage and to improve water resistance. Suitable materials include, composite coating, spray/brush/roll-on polyurea, graphine, polyethylene, fiberglass, fiber-reinforced-polymers, nanomaterials, carbon-fiber-reinforced-polymers, ceramics, and rubber. If the shell is rotational molded or blow molded then filled with the foam, the coating is preferably polyethylene. If the raft is first shaped of foam then coated, the coating is preferably polyurea. 
         [0043]    Although primarily a stationary watercraft, the raft  10  is steerable and may be propelled by a paddle or a motor to get to a desired location. In one embodiment a trolling motor  34  is attached to the raft  10  at the stern  17 .  FIG. 17  shows the motor mount  30  and  FIG. 18  shows the motor mount  30  inserted in the recess  31  in the raft. The motor mount  30  is removably secured to the raft  10  by inserting a pin through the stern  32   b , as shown in  FIG. 13 , and into a mated motor mount aperture  32   a . In a preferred embodiment the raft has a recess  25  in the stern and rear of the deck to make room for the trolling motor  34  to pivot without rubbing against the raft. See  FIGS. 12, 13 and 18 . The trolling motor  34  is removably fixed with one or more clamps  35  to the motor mount  30  at the lip  33 . Note that the motor mount  30 , also known as transom, is turned with the motor mount lip  33  facing rearward, which increases the space between the most forward-facing part of the motor mount and the front of the deck. Although only an inch or two, that small gain increases the area on the deck for the user and his gear by several percent. It also moves the motor shaft back a small percentage to help it clear the small amount of deck behind the motor mount. The deck  11  may also have a recess  43  sized to receive the bottom edge of a battery (not shown) for the trolling motor. 
         [0044]    The raft  10  may have a recess  26  in the deck  11  to receive an accessory track  44 . See  FIG. 22 . The accessory track may be removably attached with mechanical fasteners or permanently attached with adhesives. The accessory track has a groove that is shaped to receive mated accessories, such as cleats, paddle holders, anchor holders, tie-down mounts, fishing rod holders, camera mounts, cupholders, etc. 
         [0045]    To increase the area of the deck significantly, one or more rafts  10  can be removably attached together. In one embodiment a coupler  20  is used to removably attach a first raft  10  to a second raft  10 . The coupler  20  may comprise a top jaw  21  and a bottom jaw  22  separated by one or more posts  23 . A preferred embodiment of a coupler is shown in  FIGS. 14-16 . The coupler  20  is used to attach two rafts together by positioning one end or side of one raft between the top jaw  21  and the bottom jaw  22 , abutting one side of a post  23 . An end or side of the second raft is disposed between the top jaw  21  and the bottom jaw  22 , abutting the opposing side of the post. The jaws of the coupler may be resilient and hold the rafts secure in the jaws, but preferably each raft is tied to the coupler  20  and thus to each other.  FIG. 15  shows a coupler  20  tied to a cleat  24   a  in the first raft to a cleat  24   b  of a second raft. The cleats are fixed in the accessory track  44  of the raft (as described above). The shape of the coupler allows the two rafts to remain stable while an occupant moves closer the coupler because the coupler transfers the weight at the edge of one raft from that raft to the other raft, while holding the rafts together in close proximity. The now-larger raft still has a flat deck and bottom, and perpendicular sides  13  and  15 .  FIG. 16  shows two rafts coupled together with waterline w. The jaws and posts are typically rigid, but may also be resilient. Couplers can be made of any rigid material that will withstand the forces of transferring mass from one raft to the next. One such material is PVC pipe. 
         [0046]    The raft may be equipped with a number of other features that serve to make the raft more suitable for fishing. The deck  11  may have a safety line  45  attached to the raft, to secure gear to the raft. See  FIG. 19 . The safety line may be attached to the raft using anchoring hardware affixed to the deck or in the accessory track, through the deck, or tied around the whole raft. In one embodiment, four through-holes  42  are made in the raft, extending from the deck  11  to the bottom  12 . See  FIG. 19 . A rope is wound through the through-holes  42 , above the deck and below the bottom. In a preferred embodiment, a recess  46  is made in on the bottom  12  of the raft through which the safety line runs to keep it from snagging on things in the water under the raft. See  FIG. 13 . Gear may be attached to a safety line  45  with carabiners  40  or other releasable fastener. 
         [0047]      FIG. 19  also shows a series of bucket recesses, each  36 , in the deck  11 . Each bucket recess  36  is sized to receive the bottom edge of a bucket  38 , which is convenient for holding small loose items and for serving as a seat. The bucket  38  preferably has a seat top  39  or swivel seat top for the raft user to sit on. The bucket  38  can be positioned at the desired location on the raft by inserting the bucket  38  into the bucket recess  36 . The desired location may depend on how the mass of gear on the raft is distributed, the best vantage point for viewing fish or prey, best position for controlling the trolling motor, etc. The bucket  38  may have holes in its bottom or bottom flange through which a cord  37  is threaded, which in turn may be attached to the safety line  45  with carabiners  40  or other releasable fastener. See  FIG. 20 . With the bucket attached to the cord  37  with moveable fasteners, the bucket can easily be moved while the raft is in use without fear it will be lost overboard. 
         [0048]    The deck  11  may have a lip  18  around the perimeter of the raft, to help keep gear and people from sliding off the raft. See  FIGS. 21A-B . The lip  18  may be continuous but may also be discontinuous, to permit any water that gets the deck to easily drain off. The raft  10  may have through-holes at the edges or recesses that can be used as handles  41  to make it easier to carry the raft to and from the water. 
         [0049]    In some embodiments the deck may have deep recesses, typically cylindrical, conical, or frustum conical to receive gear such as fishing poles and poles used to support a tent, awning, sunscreen, hunting blind, or pedestal boat seat. In some embodiments the bottom may have deep recesses, again typically cylindrical, conical, or frustum conical, which serve to help a molded raft release from a mold or add dimensional strength to it. 
         [0050]    While there has been illustrated and described what is at present considered to be the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made and equivalents may be substituted for elements thereof without departing from the true scope of the invention. Therefore, it is intended that this invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.