|When you optimize, or tune, a strict one-design boat, it usually revolves around attempts to correct an original design flaw. With the Interclub, it is the placement of the centerboard trunk and its relationship to the mast that is the most suspect design flaw. Centerboard angle, shape and size have always been controversial, but most people seem to agree that the trunk is too far aft to keep the boat balanced properly in all conditions. As a result, the Interclub sails best with lots of rake and the centerboard canted forward.
Understanding this design flaw is the first step to optimizing you Interclub to your new Shore Sail. Your specific style of sailing may involve some minor modifications to our suggestions, but this should give you a very good starting point.
Since so much of our tuning emphasis is to try to get your boat balanced by moving the center of effort (CE) or sail area aft and the lateral resistance (LR) or centerboard forward, we should insert a warning. In very heavy air, especially during pre-start maneuvering, it is very easy to get into irons. Your CE is too far back. This is because the centerboard is all the way forward, and the rake is all the way aft. Usually the luff of the sail is being feathered, so the leech of the main puts too much pressure on the rudder. You can overcome this problem by easing the vang and setting the centerboard so the front edge is vertical. This will relieve the weather helm.
When fast paced roll-tacking is at a premium, it may also pay to have the centerboard vertical because it allows you to get the bow down after the tack. It also allows the boat to pivot on the Centerboard rather that sweeping the board through the water every time you tack.
T1 is the starting point for most of the important measurements. It is the center of the transom at deck level.
Other sailing tips for the Interclub: