UK Sailmakers’ Encyclopedia of Sails
4.10 – Storm Sails
UK Sailmakers builds storm sails to the requirements World Sailing’s Offshore Special Regulations. The Offshore Special Regulations require racers to carry three storm sails: a storm trysail, storm jib and heavy weather jib. The storm trysail and storm jib must be made out of strong Dacron or HMPE (Spectra or Dyneema).
Storm Trysail
A short triangular sail that is attached to back of the mast and is sheeted to the deck. The area of the storm trysail cannot be more than 0.175(PxE). The ORC states, “It shall be sheeted independently of the boom and shall have neither a headboard nor battens and be of suitable strength for the purpose.” If you ever plan to set a storm trysail, it is best to have a separate track on the mast for the sail. In a gale, the last thing you want to do is remove the mainsail from the mast to bend on the storm trysail.
Storm Jib
Its area is limited to five percent of the height of the foretriangle squared. The rule states that the luff of the storm jib must be shorter than 65 percent of the height of the foretriangle.
Heavy Weather Jib
Its area is limited to 13.5 percent of the height of the foretriangle squared.
If either the storm jib or heavy weather jib are made to fit a luff-groove device, the sail must have an alternative means of being attached to the stay. The most common alternative method is to have permanently attached lacings at the luff so that you can tie the sail to the stay or attached soft hanks. Both sails are designed with high clews so that waves can wash across the dec below the sails.