Google has failed to inform me of the correct T10 forestay length and where to measure it when a furler is installed. I have a Harken furler, and the previous owner's installer shortened the forestay to install it. I want a correct forestay and would like to know where to take the measurement to keep within class limits. Where is the measurement taken from on the deck end? Bear with me on the terminology: Starting at the deck, I have the original mounting plate, then a chain plate, then the furler mounting fitting (effectively the end of the forestay), then the furler drum (usually removed for racing), then the tack attachment point of the furler, then the foil. When the drum is off, I attach the jib somewhere below where the drum would be (closer to deck). Is the jib attachment point relevant for class racing (assuming you can't attach the tack lower than the deck plate)?