Tim, paddling that beast would be a handful, especially solo <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
If you want a craft like that, I think it would be better to build a proper trimaran and install oars or a pedal driven propeller (or the Hobie Mirage system [look, positive writing about an U.S invention <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" /> ]). Kayaks are not designed for sailing, so both shape and structure of the hulls need redesigning. A 20 foot wide trimaran have a lot of righting moment, I doubt an A-cat mast would be up to the loads. Neither would the hulls be once you install centerboards etc.

I read an article about a guy in the US designing and building 20 foot performance tris. X-5 was the name of the boat in the article, looked very sporty and fast, a pure sailing machine, but very possible to adapt a set of pedals for conversion to a human powered vessel. If you really are interested, I can leaf trough my collection of magazines and see if I can find it.




To try and get back on topic for the thread. It would be interesting to know wether the ply 4.9s have gained weight over time. A russian Tornado sailor told me they were replacing their wood tornados becouse they gained weight even if they were stored indoors during winter (this was in Siberia).