J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Spinnaker sail area

Spinnaker sail area is not controlled since there is flexibility on the shape. Leach length is specified as is maximum half width. It isn't really a triangle but has 3 sides that don't have to be straight lines. See class rules below.

5.12.6 Spinnaker

5.12.6.1 Minimum cloth weight is 40 grams or 0.75 oz. nominal and 0.9 oz. actual weight. Spinnakers must be made of nylon. Airex 650 is one of several approved spinnaker cloths that meet this requirement.

5.12.6.2 The maximum length of the leaches is 10.515 m. The half width at half height, measured from midpoint of the leaches to the nearest point on the centerfold shall not exceed 3429 mm (11.25′). The foot shall be contained by a 110° angle from the clews. Maximum spinnaker half width at any point on the luff shall not exceed 3429 mm.