Under the 2002 CR was it permitted to use a 'square' boom spar cross section 20 mm wide x 20 mm deep?

The 2002 CR restricted the boom spar cross section to 20 mm. The ERS definitions referred to vertical boom spar cross section and transverse boom spar cross section which led to the unfounded belief that the Marblehead boom spars were restricted in a vertical sense and a transverse sense thus permitting 20 mm 'square' section boom spars. As the term boom spar cross section was not itself defined in the ERS - the class rules effectively permitted a maximum boom spar cross section equal to a 20 mm diameter circle. A square section could be used but would have a maximum side of 14.1 mm.

The 2016 CR revert to the term 'cross section' and a diagram indicates how the limit is applied.

Boats in the class shall have rigs that comply with the 2016 CR even if initially certified before the 2016 CR came into effect.