As Doug Lord doesn't post on this site I thought I would draw your attention to a couple of interesting links on kite powered catamarans that he posted on boatdesign.net

First Yves Parliers attempt "beyond the sea"

http://www.parlier.org/beyond_the_sea/fr/multimedia.php


Then this incredible video of a kite powered "displacement" cat:

http://www.kiteboat.com/kb_videos.html

All the best

Gareth