Surfboard fins and surfboard using same

Abstract

A fin for a surfboard or other waterboard with an angled winglet on the tip of the fin. The fin may be angled from the bottom of the board. A pair of fins with mirror image shapes on a surfboard with winglets on the tips of the fins angled outward away from the center of the board.

1 . A fin for a surfboard comprising:
 a fin body element, said fin body element having a leading edge and a trailing edge, said fin element having a first side facing a first direction and a second side facing a second direction;   a fin base portion, said fin base portion attached to said fin body element at a first end of said fin element; and   a tip winglet, said tip winglet having a first end and a second end, said first end of said tip winglet attached to said fin body element at a second end of said fin element, said tip winglet attached at a first angle relative to said fin body element.   
   
   
       2 . The fin of  claim 1  wherein said tip winglet is angled from said fin body element toward said first direction. 
   
   
       3 . The fin of  claim 2  wherein said tip winglet is angled from said fin body element toward said first direction in the range of 15-60 degrees. 
   
   
       4 . The fin of  claim 2  wherein said tip winglet is angled from said fin body toward said first direction in the range of 30-50 degrees. 
   
   
       5 . The fin of  claim 1  wherein said fin body element has an asymmetric cross-section. 
   
   
       6 . The fin of  claim 5  wherein said tip winglet is angled from said fin body element toward said first direction in the range of 15-60 degrees. 
   
   
       7 . The fin of  claim 5  wherein said tip winglet is angled from said fin body toward said first direction in the range of 30-50 degrees. 
   
   
       8 . The fin of  claim 5  wherein said fin body element is substantially flat along said second side, and wherein said first side has a foil shaped cross-section. 
   
   
       9 . The fin of  claim 1  wherein said fin is made from a composite material comprising fibers, and wherein at least some of said fibers extend from said first end of said fin body element through to said second end of said tip winglet. 
   
   
       10 . The fin of  claim 8  wherein said fin is made from a composite material comprising fibers, and wherein at least some of said fibers extend from said first end of said fin body element through to said second end of said tip winglet. 
   
   
       11 . A fin system for a surfboard, said fin system comprising a first fin and a second fin, said first fin comprising:
 a fin body element, said fin body element having a leading edge and a trailing edge, said fin body element having a first side facing a first direction and a second side facing a second direction;   a fin base portion, said fin base portion attached to said fin body element at a first end of said fin element;   a tip winglet, said tip winglet having a first end and a second end, said first end of said tip winglet attached to said fin body element at a second end of said fin body element, said tip winglet attached at a first angle relative to said fin body element; and wherein the shape of said second fin is a mirror image of said first fin.   
   
   
       12 . The fin of  claim 11  wherein said tip winglet is angled toward said first direction. 
   
   
       13 . The fin of  claim 12  wherein said tip winglet is angled toward said first direction in the range of 30-50 degrees. 
   
   
       14 . The fin of  claim 11  wherein said fin body element has an asymmetric cross-section. 
   
   
       15 . The fin of  claim 14  wherein said fin body element is substantially flat along said second side, and wherein said first side has a foil shaped cross-section. 
   
   
       16 . A surfboard comprising:
 a board element, said board having a bottom surface; and   a fin system for a surfboard, said fin system comprising a first fin and a second fin, said first fin comprising:
 a fin body element, said fin body element having a leading edge and a trailing edge, said fin body element having a first side facing a first direction and a second side facing a second direction; 
 a fin base portion, said fin base portion attached to said fin element at a first end of said fin body element; 
 a tip winglet, said tip winglet having a first end and a second end, said first end of said tip winglet attached to said fin body element at a second end of said fin body element, said tip winglet attached at a first angle relative to said fin body element; and wherein the shape of said second fin is a mirror image of said first fin, and wherein said first base portion of said first fin and said second fin are attached to the bottom of said board element. 
   
   
   
       17 . The surfboard of  claim 16  wherein said first fin is attached to said board element on a first side of a centerline along said bottom surface of said board element, and wherein said second fin is attached to said board element on a second side of a centerline along said bottom surface of said board element. 
   
   
       18 . The surfboard of  claim 17  wherein said first fin body element and said second body element are angled from said bottom of said board element. 
   
   
       19 . The surfboard of  claim 18  wherein said first fin body element and said second body element are angled from said bottom of said board element in a direction wherein in said second end of said first fin body element and said second end of said second fin body element are angled away from the centerline along the bottom surface of the board element at a second angle. 
   
   
       20 . The surfboard of  claim 19  wherein said second angle is in the range of 2-20 degrees.