The Shockwave as pointed the big brother of the spitfire, designed by Ives Loday and Reg White, both Tornado legends, designers of the Vx40, check the VX40 again and you´ll see the distinctive bow shape. They also built the F18 Dart Hawk and the Dart 16 and the list goes on...
http://www.swell-catamarans.co.uk/http://www.swell-catamarans.com Close enough - It was actually Yves and Robert White, Reg has finally retired. Robert is a Tornado World Champion.
I saw the Shockwave in Brightlingsea, it is indeed like a very large Spitfire. Tim, you should have asked the Irish Agent

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PS Add the Shadow, SL16, Topper Topaz 14 & 16 to that list.