Tarleton State University
At Tarleton during my freshman year, we were required to build many projects. One of those projects was a cardboard boat to compete at Arlington in the Cardboard Boat Regatta. We built a Russian style boat. First, we cut the frame out with a CNC router and then used the form to build the card board boat.
We used ice picks to hold the cardboard pieces together. Packaging tape was used to cover the edges of the cardboard and the seams of the boat, so it could be more easily waterproofed.
The boat turned out with really nice looking lines. It was stiff, strong, slick, maneuverable, and fast. The only problem with the boat was having two rookie drivers and not enough layers of paint to keep the water out.