Several Sailmakers have intentionally attempted to circumvent IRC rules 2.4 and 2.5 by developing headsail foot shelf profiles that artificially reduce the headsail measurements, reducing the IRC rating without a corresponding reduction in performance. To do this the curve of the foot is exaggerated to create a far larger foot shelf than required. This means that the measured tack point and clew point are not extended, and therefore move up the luff and leech, artificially reducing the sail’s dimensions.

IRC Rule Notice 2012/02 addresses this issue with the introduction of headsail Foot Offset.

Previous IRC Notices and Interpretations


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