IRC

IRC is a time-correction rating rule for keelboats, jointly owned by the Royal Ocean Racing Club and the Union Nationale pour la Course au Large. Each boat’s measurements (length, weight, draft, rig and sail dimensions, and features such as a movable keel or asymmetric kite) yield a single Time Correction Coefficient, applied time-on-time. Unlike ORC, the IRC formula is not published, which is meant to discourage designing to the rule and to keep older boats competitive. It is the dominant handicap for amateur offshore and inshore racing in Britain, France, and much of the Commonwealth.