Hi Andrew,
I guess it would have been my Blade you saw down at Weston. The boat's actually kept at Datchet, but I was down there for the cat open drift-a-thon last year.
I've never sailed a fast asymmetric monohull, but I've seen enough people swimming near RS700s and the like to know that single-handing a cat+spi is a different game. Getting the last few percent of speed is still a big challenge, but it doesn't take long to learn how to stay dry and have a blast.
It wasn't you I gave a ride to in Garda this summer, was it?
Paul