There are many ways to mark jib and genoa leads, and you need to find what works best for your boat. If you’re sailing a one-design, there’s likely a common way your competitors mark their tracks. Using the most commonly accepted system helps you better when settings with friends or competitors. On the J/70, for example, we mark the deck even with the aft end of the car and then number the marks based on the preferred tuning guide. That way, the marks are highly visible and the car position is easy to reproduce. Some boats mark the deck even with the pin on the car. On boats with purchase systems rather than pin-stop cars, we number the entire track with marks spaced 3 to 6 inches apart, depending on the size of the boat.