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IACA Technical Committee Clarify 'A' Class Rudder Measurements

The IACA technical committee and World Sailing agree a clarification.

A rudder hanging clarification was posted on the IACA website 27/1/16 to clarify our interpretation of rudder hangings and since that time the issue has been raised by a number of individuals and measurers as to how this interpretation can be ruled on and how a sailor is to know if he is class legal or not.

As stated in my advise of 27/1/16 the original interpretation was put in place to restrict the use of extended rudder gantries etc. and until recently appeared to adequately cover this. Rapid change has taken place over the past year with the advent of foiling and rudder design and rudder attachment and position have reached levels that our interpretation does not really cover.

The present interpretation (No.7) basically states the rudder hangings can be no larger and no further aft than required to support the rudder and no further aft than required to provide steerage or extend the overall length of the rudder assembly. Without actual measurements this is a judgment call only and impossible to rule on.

The only measurement we do state as a guide is that the rudder assembly in a fully down position shall fit within 5.79m from forward extremity of hull (i.e. 30cm from stern)

With the pending Worlds in Medemblik, IACA needed to have this matter addressed and sought the guidance of World Sailing (formerly ISAF) who agreed with the issues we are facing. They advised the only part of the interpretation that we could rule on was 5.79m. As a World Sailing class they are the controlling body for all our rules and no rules or interpretations can be put in place without their approval. We have now simply run out of time to formulate a new rule or interpretation in terms of our constitution before the Worlds.

World Sailing has recommended that for the 2016 Worlds that the overall length of the hulls remains at 5.49m (Refer Rule 3) and the overall boat length (which is to include the rudder hangings and rudder appendage) measured parallel with boat centerline in a fully down position is not to exceed 5.79m. This gives a clear measurement that can be ruled on and a clear guide for sailors to follow for Medemblik. This is a temporary measure only and will remain until a new rule or interpretation to cover this is devised and put into place in terms of our constitution.

Countries should now begin discussion with their members on this matter and submit proposals if the necessary support is obtained from other countries. Matter will be raised as an agenda item at the WGM.

This situation is not ideal, but hopefully provides some temporary clarity.

All measured boats to date should already fit within the 5.79m guide.

Rule 3 has not changed and continues to limit the overall hull length at 5.49m, excluding rudder hangings. It also continues to limit the width of the rudder assembly to a maximum width of 76mm within 153mm of the bottom of the hull.

Rule 4 continues to limit maximum width of hull appendages in all positions to 2.3m.

Rule 8 continues to limit minimum width below waterline of hull appendages to 0.75m from centre line.

Graeme Harbour

Chairman IACA

Technical Committee


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