As an organisation, Nigel Burges, to my extend. But not all the individuals there are on the same level.
As an individual...hmmm, old foxes, like Herbert Dahm, Sten Rasmussen, Mike Kelsey Senior (rest in peace) would come to my mind ten years ago (when I was a kid, basically), but I can't find an equivallent personality on the market of today.
Paolo Vitelli, has as does Norberto Ferretti to much of a local (italian) image on the global market, I could see one of them well in covering the Med but not the world though. I should have say Gerard Rodriguez, but the man retired and the cousins are definetly not on the level.
In US you would probably want to involve someone as Marine Max or perhaps an individual as Irwin Jacobs?
But globaly, as a yachtsman today there isn't an individual strong enough to acy as an testimonial. Just take a look at Russell Coutts, a man won the AC and yed his image is not enough to launch a small sailing racer (RC 44) onto the market (
http://www.russellcoutts.net/)