Oops sorry Doug, those epoxy fumes are taking a while to clear. On this bulletin board about 1 or maybe two months ago there was a question posed along the lines of 'polestyrine kayaks'. In the thread, a poster provided a link to a 'slipper' - type surfkayak made of epoxy over polestyrine (I think it was designed by a Californian engineering student). It might be worth a look if you can use the search system better than me (I can't seem to control it).

The design would still come off second best with rocks, but it would probably perform like a state of the art white water kayak and the graphics were great.

Good luck

Pete