Storable, sickle-shaped sailboat mast utilizing constant curvature and a curved mast extension

Abstract

A sailboat mast including a straight lower portion and an arcuate upper portion. The arcuate upper portion has an aerodynamically efficient cross section designed to reduce drag. At least the arcuate upper portion is free to rotate with respect to the boat's hull in order to position the mast in line with the airflow for windward sailing, perpendicular to the airflow for downwind sailing, and at other appropriate angles for other conditions. The arcuate upper portion of the mast facilitates storage of the mast along a curved gunwale. The mast preferably incorporates a curved mast extension allowing an increase in the sail area beyond what is possible for a one-piece mast that is storable within the length of a boat.

1 . A mast assembly for a sailing vessel having a hull, comprising:
 a. a mast having an arcuate portion, said arcuate portion having a lower extreme and an upper extreme; and   b. a pivot joint between said arcuate portion and said hull, wherein said pivot joint allows said arcuate portion to rotate with respect to said hull.   
   
   
       2 . A mast assembly as recited in  claim 1 , further comprising:
 a. a boom, oriented approximately horizontally when in use;   b. wherein said boom has a proximal end located proximate said arcuate portion and a distal end located distal to said arcuate portion; and   c. wherein said proximal end of said boom is joined to said mast so that said boom and said arcuate portion rotate together.   
   
   
       3 . A mast assembly as recited in  claim 2 , wherein said mast further comprises a straight portion located proximate said lower extreme of said arcuate portion. 
   
   
       4 . A mast assembly as recited in  claim 3 , wherein said pivot joint is located between said arcuate portion and said straight portion. 
   
   
       5 . A mast assembly as recited in  claim 3 , wherein said pivot joint is located between said straight portion and said sailing vessel. 
   
   
       6 . A mast assembly as recited in  claim 2 , wherein said pivot joint is located proximate said lower extreme of said arcuate portion. 
   
   
       7 . A mast assembly as recited in  claim 2 , wherein said boom is angularly offset from the plane in which said arcuate portion of said mast lies. 
   
   
       8 . A mast assembly as recited in  claim 3 , wherein said boom is angularly offset from the plane in which said arcuate portion of said mast lies. 
   
   
       9 . A mast assembly as recited in  claim 4 , wherein said boom is angularly offset from the plane in which said arcuate portion of said mast lies. 
   
   
       10 . A mast assembly as recited in  claim 5 , wherein said boom is angularly offset from the plane in which said arcuate portion of said mast lies. 
   
   
       11 . A mast assembly as recited in  claim 7 , wherein said angular offset is variable. 
   
   
       12 . A mast assembly as recited in  claim 8 , wherein said angular offset is variable. 
   
   
       13 . A mast assembly as recited in  claim 9 , wherein said angular offset is variable. 
   
   
       14 . A mast assembly as recited in  claim 10 , wherein said angular offset is variable. 
   
   
       15 . A mast assembly for a sailing vessel having a hull, comprising:
 a. a mast having an arcuate portion, said arcuate portion having a lower extreme and an upper extreme;   b. a pivot joint between said arcuate portion and said hull, wherein said pivot joint allows said arcuate portion to rotate with respect to said hull;   c. an arcuate mast extender, slidably connected to said arcuate portion of said mast; and   d. wherein when said arcuate mast extender is extended upward, said arcuate mast extender extends the overall height of said mast assembly.   
   
   
       16 . A mast assembly as recited in  claim 15 , further comprising:
 a. a boom, oriented approximately horizontally when in use;   b. wherein said boom has a proximal end located proximate said arcuate portion and a distal end located distal to said arcuate portion; and   c. wherein said proximal end of said boom is joined to said mast so that said boom and said arcuate portion rotate together.   
   
   
       17 . A mast assembly as recited in  claim 16 , wherein said mast further comprises a straight portion located proximate said lower extreme of said arcuate portion. 
   
   
       18 . A mast assembly as recited in  claim 17 , wherein said pivot joint is located near middle of straight portion and said straight portion. 
   
   
       19 . A mast assembly as recited in  claim 17 , wherein said pivot joint is located between said straight portion and said sailing vessel. 
   
   
       20 . A mast assembly as recited in  claim 16 , wherein said pivot joint is located proximate said lower extreme of said arcuate portion.