Tube rail waterboard

Abstract

A waterboard includes channels of continuously variable depth and angle.

1 . A waterboard, comprising:
 an elongated foam core comprising a nose portion, a body portion and a tail portion;   an upper rail and a lower rail defining respective upper and lower chines running from said nose portion to said tail portion; and   a longitudinal channel between said upper and lower chines, said channel intersecting said upper and lower chines; said channel having an increasing depth and a decreasing angle between said nose portion and said tail portion.   
   
   
       2 . The waterboard of  claim 1 , wherein said longitudinal channel extends to said tail portion. 
   
   
       3 . The waterboard of  claim 1 , wherein said longitudinal channel does not extend to said nose portion. 
   
   
       4 . The waterboard of  claim 3 , wherein said longitudinal channel begins at a location that is about ⅔ to ¾ of the length of the waterboard from the tail portion. 
   
   
       5 . The waterboard of  claim 4 , wherein said longitudinal channel begins at a location that is about ¾ of the length of the waterboard from the tail portion. 
   
   
       6 . The waterboard of  claim 4 , wherein said longitudinal channel begins at a location that is about ⅔ of the length of the waterboard from the tail portion. 
   
   
       7 . The waterboard of  claim 1 , wherein said longitudinal channel has a contour, wherein said contour comprises a circular arc. 
   
   
       8 . The waterboard of  claim 1 , wherein said longitudinal channel has a contour, wherein said contour comprises a parabolic arc. 
   
   
       9 . The waterboard of  claim 1 , wherein said longitudinal channel has a contour, wherein said contour comprises a hyperbolic arc. 
   
   
       10 . The waterboard of  claim 1 , having sides having a generally convex cross-section. 
   
   
       11 . The waterboard of  claim 10 , wherein said sides having a generally convex cross-section are disposed closer to said nose portion than are said longitudinal channels. 
   
   
       12 . The waterboard of  claim 1 , further comprising an outer layer bonded to said elongated foam core. 
   
   
       13 . The waterboard of  claim 12 , wherein said outer layer comprises polyethylene foam. 
   
   
       14 . The waterboard of  claim 1 , further comprising a sheet of polymeric film. 
   
   
       15 . The waterboard of  claim 14 , wherein said sheet of polymeric film comprises a top sheet. 
   
   
       16 . The waterboard of  claim 14 , wherein said sheet of polymeric film comprises a bottom sheet. 
   
   
       17 . The waterboard of  claim 14 , comprising a top sheet and a bottom sheet of polymeric film. 
   
   
       18 . The waterboard of  claim 12 , further comprising a sheet of polymeric film bonded to said outer layer. 
   
   
       19 . The waterboard of  claim 18 , wherein said outer layer comprises an outer foam layer. 
   
   
       20 . The waterboard of  claim 18 , wherein said sheet of polymeric film bonded to said outer layer comprises a sheet selected from a bottom sheet, a top sheet, and a bottom sheet and a top sheet.