Make sure that you go for one with a quick release system in case of trouble.

I'd not reccommend the Magic Marine harnesses as I have one and find that the webbing constantly slips under my weight 210lb) and if you're 230lb then I reckon that there's a good chance that they will slip for you. Don't know if lighter sailors fare any better with these harnesses but I can only go by my experience.

I've been very impressed with the Neil Pryde Harnesses which have a ratchet system rather than webbing. They have also been designed and tested by catamaran sailors in our club. I don't know whether you can get them where you are, but for me in Hong Kong, I can order online at www.asap-direct.com (if you go to the site, the link is in the "new to store" on the left side of the webpage)