I think most fiberglass factory production cats are about 100lbs. heavier than the could be if the industry would switch to carbon fiber hulls, masts, boards, rudders, beams and sails.
The argument against it is "Carbon is too expensive..." but if the entire industry were to swith and suppliers could make it in bulk, wouldn't the cost come down quite a bit?
The light aircraft industry is slowly changing over from aluminum to carbon and the prices are pretty much the same but the finished product is both lighter and stronger.