I've known David since Expo '86 in Vancouver, where I was displaying Winnebiko II and he was zipping around on his newly minted Vacuum Velocipede.   He has been a constant source of design ideas, hands-on fabrication help, and amusing commentary ever since... and is a mechanical engineer of the first order.

The molds for this boat were generated directly from the CAD files by a machine David built that still amazes me... rapid prototyping Writ Large.  It would lay down a layer of sand, inject wax from a nozzle carried by a huge X-Y plotter assembly according to that slice of the model, then move up .1" and repeat.  Drain the loose sand, and voila!  A sand-wax plug with a corduroy surface, ready, after some smoothing, to pull a mold.  Cool stuff.

That's Andrew Letton in the photo below, about a year ago.  I'm bugging David for some more recent images of this little rocket ship... which, by the way, can fold for cartopping.