Watercraft Fin

Abstract

In one aspect, the present invention provides a watercraft fin including a first side surface and a second side surface wherein at least one of the first side surface or the second side surface includes a plurality of dimples.

What is claimed is: 
     
         1 . A watercraft fin including a first side surface and a second side surface wherein at least one of said first side surface or said second side surface includes a plurality of dimples. 
     
     
         2 . A fin as claimed in  claim 1  wherein said dimples are substantially circular and have a diameter of between 2.0 mm and 4.5 mm. 
     
     
         3 . A fin as claimed in  claim 1  wherein said dimples are substantially circular and have a diameter of between 3.8 mm and 4.3 mm. 
     
     
         4 . A fin as claimed in  claim 1  wherein said dimples are substantially circular, have a diameter of between 2.0 mm and 4.5 mm, and have a depth of between 0.1 mm and 0.5 mm. 
     
     
         5 . A fin as claimed in  claim 1  wherein said dimples are substantially circular, have a diameter of between 2.0 mm and 4.5 mm, and have a depth of between 0.2 mm and 0.5 mm. 
     
     
         6 . A fin as claimed in  claim 1  wherein the diameter of said dimples is about 4.036 mm and the depth of said dimples is about 0.325 mm. 
     
     
         7 . A fin as claimed in  claim 1  wherein midpoints between adjacent dimples are between 3.7 mm and 4.5 mm apart. 
     
     
         8 . A fin as claimed in  claim 1  wherein edges of adjacent dimples are between 0.2 mm and 0.5 mm apart. 
     
     
         9 . A fin as claimed in  claim 1  wherein edges of adjacent dimples are between 0.3 mm and 0.4 mm apart. 
     
     
         10 . A fin as claimed in  claim 1  wherein at least one of said first side surface or said second side surface includes between 300 and 900 dimples. 
     
     
         11 . A fin as claimed in  claim 1  wherein said fin includes a base which in use would join the fin to a watercraft, and wherein said dimples are arranged in lines, said lines running between 170 degrees and 190 degrees relative to said base. 
     
     
         12 . A fin as claimed in  claim 1  wherein said fin includes a base which in use would join the fin to a watercraft, and wherein said dimples are arranged in lines, said lines running substantially parallel to said base. 
     
     
         13 . A fin as claimed in  claim 1  wherein said fin includes a leading edge and a trailing edge, and wherein said dimples increase in size from said leading edge to said trailing edge. 
     
     
         14 . A fin as claimed in  claim 1  wherein said fin includes a leading edge and a trailing edge, and wherein said dimples increase in size from said leading edge to said trailing edge, wherein said dimples increase in size by increments of about 1.0 mm, and diameters range from about 2.0 mm adjacent said leading edge to about 4.0 mm adjacent said trailing edge. 
     
     
         15 . A fin as claimed in  claim 1  wherein said fin includes a leading edge and a trailing edge, and wherein said dimples are located behind the widest point of the fin, said widest point being determined from a cross section of said fin between said leading edge and said trailing edge. 
     
     
         16 . A fin as claimed in  claim 1  wherein the dimples are hexagonal, triangular, rectangular, oval, or square. 
     
     
         17 . A fin as claimed in  claim 1  wherein said fin includes a tip and said dimples are located proximate to said tip. 
     
     
         18 . A fin as claimed in  claim 1  wherein said dimples are located in areas where laminar separation of the water from the fin occurs. 
     
     
         19 . A watercraft fin, comprising:
 (a) a lift generating first side surface and a second side surface;   (b) at least one of said first side surface or said second side surface including a plurality of dimples, said dimples being substantially circular and having a diameter of between 3.8 mm and 4.3 mm, and a depth of between 0.2 mm and 0.5 mm;   (c) said dimples arranged such that midpoints between adjacent dimples are between 3.7 mm and 4.5 mm apart, or edges of adjacent dimples are between 0.3 mm and 0.4 mm apart.