Hard to believe, but I actually found a couple of photos of my very first tunnel boat. The year was probably 1977. It was designed by Dave Knowlen, an engineer at Boeing. Dave also designed limited hydroplanes and I think he designed the canard Circus Circus(from the model canard concepts of Ed Fisher) and then the conventional Circus Circus. The boat was built from plywood and it seems like it was 30" long.
Thanks to J.R. Caines for converting the photos to a digital format. That's my son, Paul, holding the boat. Paul is now 46 and probably 5 at the time of the photo.