The Civil Engineering department of my alma mater, the University of Wisconsin-Madison (I pause a moment;wistful look on my face), participates in this competition. It's pretty amazing -- the hull was only about 3/8" thick or so, if memory serves. Of course there's no aggregate as in your ususal concrete, so it has a very smooth, pottery-like appearance which the teams paint on the exterior. They even have concrete thwarts, which are probably reinforced with wire mesh as I believe the hull is.

Dean

> ... generally work with concrete but that is not a good kayak material.

> I which I had a photographic memory, but there is a group that builds and
> races concrete canoes every year. This year the winner was built by some
> university and weighed @ 25lbs. I read it, so it must be true!!

> Dave