Ok the stealth 'r' main might have been acceptable to the F16 class but the huge jib? Did the existing mast accomodate the extra F16 main area? Didn't all the 20 footers you mention come after the formulation of the 20 foot formula? The existing 19 - 20' fleet boats were no longer the flavour of the month, but many owners held onto them. They reluctant to commit expense to another class showing little benefit over what they sailed. Result in UK - dilution of some classes and failure of the formula.

Cheshirecatman