My jib is new and my main looks good, I think. How can I tell when my mainsail’s racing shape is not what it should be?
As all sails age the draft or maximum depth of the sail tries to find its way to the middle of the sail between luff and leech. In most classes this area is very close to or in some cases on the inboard tips of the mainsail battens. When the sail was originally built it had a fair curve from luff to leech. This shape more than likely had its maximum depth or draft somewhere between 30% and 40% aft of the luff. The sails shape eventually gets flatter as you move aft towards the leech. What happens when the sail cloth or fabric starts aging or breaking down is that the high load area of the inboard tips of the battens actually takes that original fair , flat shape and actually makes what we call a hinge effect right in that area. On a sail that has broken down you will actually see a big shape change now just in front of the inboard batten tips. Also, you will see larger amounts of what we call crazing or fabric stress in these same areas. This is very visible. Once a sail has reached th
