• 5.2 Mainsail The headboard may be of any material not exceeding 153 mm in weight and length. Including the luff rope, the total weight of the head shall not exceed 191 mm.
    • 5.2.1 The length of the leech shall not exceed 6629 mm. All mainsails built prior to November 1, 1993 shall be grandfathered in regards to leech measurement.
    • 5.2.2 Total weight measurements for the mainsail shall be taken at 3/4 height, 1/2 height. 1/4 height measuring points on the leech to the nearest points on the luff. The total weight measurements, include the luff rope, shall not exceed: 3/4 height = 1219 mm; 1/2 height = 1994 mm; 1/4 = 2438 mm. The leech shall not be hollowed to evade weight measurements.
    • 5.2.3 The mainsail shall not exceed rule 4.0.4 and rule 4.2.1 (E = 2591 mm and p = 6248 mm).
    • 5.2.4 The mainsail shall have four battens that divide the leech into five equal parts. The top two batten shall be full length. The bottom two battens shall not exceed 991 mm. The maximum weight for the battens shall be 50 mm.
    • 5.2.5 The mainsail shall be loose footed. There shall be a non-adjustable slug attached at the tack and at the clew. The foot round shall not exceed 102 mm. A cunningham cringle within 254 mm of the clew is permitted. A leech line is permitted.