Abstract: A sailboat comprising at least one mast, first and second pairs of primary half yards pivotally mounted on and vertically spaced apart along the mast for pivoting about the mast between first and second positions wherein the members of each pair extend from the same axial location along the mast to define 180.degree. and 0.degree. angles therebetween, respectively, and means for mounting a sail between the vertically spaced apart members of each pair of primary half yards, whereby the sailboat is convertible between square-rigged when the primary half yards are in the first position and fore-and-aft rigged when the primary half yards are in the second position.