August 2018 changes to 2018 65 Class and Marblehead class rules. Why? And why have the Ten Rater and A Class rules not been changed?

The 65, M, 10R and A class rules have certain restrictions and limitations relating to booms. In 2018 it became apparent that the ERS definition of a boom - a spar attached at one end to a mast spar or a hull and on which the clew of a sail is set .... and its fittings - meant that the class rules did not work well for swing rigged boats.

The class rules for the 65 and Marblehead class rules have been changed by the IRSA EC - effective 1st August 2018 - acting to maintain the previous common understanding of the class rules. The A Class does not permit swing rigs so the class rules need no change. One DNM has provided a proposal to change the class rules in the 10R Class and so this will pass through the formal procedure for dealing with such proposals.

Please see the related Q&A - Does a typical rc yacht balanced headsail boom meet the ERS definition of a boom?