Originally Posted by CrazyRu
You can buy beach catamaran and carry folding/inflatable/small rigid kayak for fun.
I tried to go your route some 20 years ago, modifying a kayak into fully blown trimaran. It never worked for me. Chief from Watertribe has tried to go this route without much success. Every year somebody trying to bring some kayak based paddling/sailing, supposedly fast trimaran into Everglades Challenge, I have never seen one succeeded, exept Balogh system and Hobie AI.
There are too many design limitations. To make weatherly trimaran you have to build very strong and stiff platform. It becomes too heavy very fast for one person to handle, to paddle, to cartop…
Did you look at Raptor outrigger?
Hydrovisions Innovative High-Performance Watercraft Design
Speaking of Watertribe...
I wonder if something a bit more substantial, like these Wa'apa sailing canoes, might be more along the lines of what James needs. It's tempting to call them sailing kayaks, but they have more heft.
Incidentally, and here I'm guessing, but I believe this video was shot from Matt Layden's little Sand Flea sailing pram at the start of the 2007 E.C.
Wa'apa Sailing Canoes at E.C. 2007