Multi-function surfboard fin and fin box attachment device

Abstract

A surfboard having a hull, a multi-function fin and multi-function fin receiving box system. This invention incorporates the use of a variety of fins, fin bases including multi-tab, rectangular and positioning inserts. Receiving box and locator inserts are optionally configured so that the fin may be adjustable positioned and secured in a three-dimensional configuration. The fins positioning may include fore and aft, cant angel and angel of attack positioning. The fin positioning may be adjusted through recessed wedge or other shaped receiving voids and insert elements positioned in and around the structural wall areas of the receiving box. The interior wall surfaces of the fin-securing cavity accommodate the positioning of the fins base attachment and aligning structures and are constructed with various extended, receiving, positioning, supporting and securing features.

1 . An adjustable, interchangeable and removable fin and fin receiving box and insert assembly for mounting in a cavity of a watercraft, the adjustable, interchangeable and removable fin and fin receiving box comprising: 
 a fin box positioned in the cavity of the watercraft, the fin box having a top surface a lower surface a longitudinal length with a front end and a rear end, the fin box incorporating a fin and insert capable receiving main and secondary cavities:    a fin member adjustable, interchangeable and removable mountable in the fin receiving box cavity or cavities, a fin extending into the receiving cavity or cavities permitting adjustable, interchangeable, removable and securable positioning.    
   
   
       2 . The assembly of  claim 1  wherein the main receiving fin box cavity selectively comprises: a plurality of positioning members positional in the main box cavity forwardly, rearward, under and along side of the fin member to adjust, position and secure the fin base member or members, the positioning members being configured to position and adjust the fore and aft, the cant and the angle of attack of the fin member.  
   
   
       3 . The assembly of  claim 1  wherein the main receiving fin box cavity walls comprises: an extended vertical portion for selectively removing during installation in a watercraft.  
   
   
       4 . An adjustable removable fin insert assembly for mounting inside a fin base-receiving cavity of a watercraft, the adjustable fin insert assembly comprising: 
 a fin positionable in the cavity of the fin base in a three-dimensional manner incorporating a fore and aft, a cant and an up and down angel of attack securable positionable in a fin receiving box.