03-11-2010, 23:28
ORC RULES
Introduction
ORC Rating systems (ORC International and ORC Club) use the International Measurement System
(IMS) as a measurement platform and the ORC Velocity Prediction Program (VPP) to rate boats of
different characteristics in size, hull and appendages shape and configuration, stability, rig and sails
measurement, propeller installation and many other details affecting their theoretical speed.
Boat ratings are calculated from the predicted boat speeds, calculated for 7 different true wind speeds
(6-8-10-12-14-16–20 knots) and 8 true wind angles (52°-60°-75°-90°-110°-120°-135°-150°), plus
the 2 “optimum” VMG (Velocity Made Good) angles: beating (TWA=0°) and running (TWA=180°),
which are calculated obtaining an optimum angle at which the VMG is maximized. From the matrix
of predicted performances a variety of handicaps are derived, and corrected times can be obtained
selecting from a variety of options that range from the single number and triple number scoring
based on Time-on-Distance or Time-on-Time to the “automated” methods such as the simple
Performance Line Scoring (PLS) or the more sophisticated Performance Curve (PCS).
Introduction
ORC Rating systems (ORC International and ORC Club) use the International Measurement System
(IMS) as a measurement platform and the ORC Velocity Prediction Program (VPP) to rate boats of
different characteristics in size, hull and appendages shape and configuration, stability, rig and sails
measurement, propeller installation and many other details affecting their theoretical speed.
Boat ratings are calculated from the predicted boat speeds, calculated for 7 different true wind speeds
(6-8-10-12-14-16–20 knots) and 8 true wind angles (52°-60°-75°-90°-110°-120°-135°-150°), plus
the 2 “optimum” VMG (Velocity Made Good) angles: beating (TWA=0°) and running (TWA=180°),
which are calculated obtaining an optimum angle at which the VMG is maximized. From the matrix
of predicted performances a variety of handicaps are derived, and corrected times can be obtained
selecting from a variety of options that range from the single number and triple number scoring
based on Time-on-Distance or Time-on-Time to the “automated” methods such as the simple
Performance Line Scoring (PLS) or the more sophisticated Performance Curve (PCS).
Tra me e il mare comanda il tempo...
Leandro
Leandro
