Center of lateral resistance (CLR)

The center of lateral resistance (CLR) is the effective point through which the net hydrodynamic side force on the underwater hull acts when the ship moves with a drift angle or under helm. In sailing-yacht and maneuvering analysis it is taken as the centroid of the lateral underwater profile (the projected lateral plane), and its position relative to the center of effort of the sails or the center of pressure of the rudder governs the yawing balance: lead or trim. A CLR forward of the driving force gives weather helm; aft gives lee helm. It is a profile-area approximation, not a measured hydrodynamic center, which shifts with speed and drift angle.