For some reason, too many sailors believe that the relative position of CE (center of effort) to CLR (center of lateral resistance) is the main (or only) cause of weather helm. Time and again, I hear this dockside advice: "So you have weather helm, huh? Well, you obviously have too much mast rake. Just shorten the forestay and the problem will go away." Even if the rake is fine, you can still have weather helm, so shortening the forestay may not address the real problem. However, you CAN move the CE forward to counteract weather helm from other sources. This can be done far more easily and effectively than shortening the forestay, The answer is....(drum roll please) sail trim!! The center of effort is the single point where all of the wind-induced force distribued over a sail can be assumed to act. It's the same concept as "center of gravity". The CE has two main properties; location and force. Assuming a typical triangular sail with uniform wind pressure over its entire surface ("perfect trim") the CE would be located at the centroid of the triangle, While the definition of the centroid of a triangle escapes me at the moment, I do know it is 1/3 the height of the sail above any side. That would place it at a point 1/3 of the sail height above the foot and 1/3 the foot length forward of the leech. If the sail trim is less than perfect, the actual CE on the sail may be forward, aft, above or below the centroid. More importantly, the force on the sail will be lower than the maximum available with perfect trim. On a typical sailboat, both mainsail and jib have their own CE. The two CE's can be combined mathemically to form a single CE for the sailplan. The location of that CE depends on the force and location of each sail's CE. It's the "CE" people refer to when they discuss CE position relative to CLR. Let's complicate matters further. The entire dicussion so far assumes that the sails are trimmed tight to the centerline of the boat. That's not really the case, so the slight angle of the sails to the centerline means that the CE of each sail is actually forward of where it should be theoretically. More on this in a bit, Here's where it gets simple again. You can use sail trim to adjust the force and location of the CE of each sail. As mentioned earlier, the CE of the sailplan is the single-point equivalent of the CE's of the two sails. By adjusting the force and position of one sail's CE relative to the other (using the sheets, traveler, jib leads, boom vang, cunningham or backstay adjuster), the overall CE of the sailplan can be moved to your advantage. For example, powering up the headsail and easing the main (or the traveler) reduces the force on the main AND moves its CE forward (easing the main allows the boom to swing away from the centerline of the boat and forward). Since the main is less powerful compared to the headsail, the CE of the sailplan moves forward and weather helm is reduced. This can be done in seconds, without leaving the cockpit. How do you know when you've got it right? The helm provides feedback. Think of the rudder as the bit of influence needed to bring everything into balance. A well-balanced sailplan needs very little rudder to keep the boat on track. Why not try putting the forestay turnbuckle wrench down and reaching for the winch handle instead? Happy sailing. Peter H23 "Raven"