Sailing What is the rule of 12th? March 3, 2026 by pups | Leave a Comment The Rule of 12ths is a simple yet effective guideline used in sailing to determine the optimal sail trim for various wind conditions. It suggests that for optimal performance, the clew of the mainsail should be aligned with the last 12 inches of the boom. Understanding the Rule of 12ths in Sailing The Rule of […] Read more »