There was (is) a Zygal Boatyard in Whitstable and Sharp Catamarans in Whitstable were the builders in 1981. I also know that there was a Condor fleet there in the Eighties. It is not far from Brightlingsea, where Reg White is based.
In 1970 a guy called Arthur Edmonds was the Condor builder and brought the first Condors to Ireland. He came over and raced against the Shearwaters to prove that the Condor was faster.