Surfboard fin and method for use thereof

Abstract

A surfboard fin having mounting elements ( 95 ) for removably attaching the fin to a fin box of a surfboard may have an angle of attack ( 110 ) that is defined by a line from the leading edge ( 92 ) to the trailing edge ( 94 ) of the fin. The angle of attack ( 110 ) may be offset from a mounting axis ( 112 ) defined through the mounting elements of the fin. The offset enables a surfboard to be tuned to create directional performance characteristics for the surfboard.

What is claimed is: 
     
         1 . A fin for a surfboard including:
 a. a fin element extending substantially along a fin plane from a forward end to a rearward end, the fin element including:
 i. a leading edge at a forward end of the fin element; 
 ii. a trailing edge at a rearward end of the fin element; 
   b. at least one mounting element extending from the fin element for removably mounting the fin into a complementary engagement element of a surfboard, the at least one mounting element having a mounting axis that aligns with an axis of the complementary engagement element in a plane of the surfboard;   c. wherein an angle of attack is defined by a line:
 i. that is in a plane that is substantially perpendicular to the fin plane and that substantially corresponds, when the fin is mounted to a surfboard, to the plane of the surfboard; and 
 ii. that passes from the leading edge to the trailing edge 
   d. wherein the angle of attack is at an angle to the mounting axis.   
     
     
         2 . The fin of  claim 1  wherein the fin element comprises an outward face and an inward face, wherein the outward face is defined as the face of the fin element that the angle of attack is angled towards in the direction from the leading edge to the trailing edge. 
     
     
         3 . The fin of  claim 2  wherein the inward face is convex. 
     
     
         4 . The fin of  claim 2  wherein a curved portion of the inner face curves toward the outward face in the direction from the leading edge to the trailing edge. 
     
     
         5 . The fin of  claim 4  wherein the curved portion is at least 25% of a length of the fin from the trailing edge. 
     
     
         6 . The fin of  claim 1  wherein the angle of attack is at least 0.25 degrees relative to the mounting axis. 
     
     
         7 . The fin of  claim 1  wherein the angle of attack is at least 1 degree relative to the mounting axis. 
     
     
         8 . The fin of  claim 1  wherein the angle of attack is at least  1 . 5  degrees relative to the mounting axis. 
     
     
         9 . The fin of  claim 1  wherein an offset between the angle of attack and the mounting axis is a maximum at an edge of the fin element where the at least one mounting element extends from the fin. 
     
     
         10 . A method of configuring the turning characteristics of a surfboard including:
 a. selecting at least one fin to be removably mounted to the surfboard in a plane substantially perpendicular to a plane of the surfboard, the at least one fin including:
 i. a fin element extending substantially along a fin plane from a forward end to a rearward end, the fin element including:
 1. a leading edge at a forward end of the fin element; 
 2. a trailing edge at a rearward end of the fin element; 
 
 ii. at least one mounting element extending from the fin element for removably mounting the fin into a complementary engagement element of the surfboard, the at least one mounting element having a mounting axis that aligns with an axis of the complementary engagement element in a plane of the surfboard; 
 iii. wherein an angle of attack is defined by a line:
 1. that is in a plane that is substantially perpendicular to the fin plane and that substantially corresponds, when the fin is mounted to the surfboard, to the plane of the surfboard; and 
 2. that passes from the leading edge to the trailing edge; 
 
 iv. wherein the angle of attack is at an angle to the mounting axis; 
   b. mounting the at least one fin to the surfboard.   
     
     
         11 . The method of  claim 10  including mounting the at least one fin on a centerline of the surfboard. 
     
     
         12 . The method of  claim 10  including mounting the at least one fin to a side of the centerline of the surfboard. 
     
     
         13 . The method of  claim 12  wherein selecting the at least one fin includes selecting at least two fins and mounting the at least two fins to opposite sides of the centerline of the surfboard. 
     
     
         14 . The method of  claim 13  wherein the at least two fins include angles of attack that have equal magnitude but opposite direction. 
     
     
         15 . The method of  claim 13  wherein the at least two fins include angles of attack of different magnitude. 
     
     
         16 . The method of  claim 13  wherein the angles of attack of the at least two fins converge at a point that is displaced laterally of the centerline of the surfboard.