You may want to research the Waters & Sons Paper Boat Company in Troy NY. They manufactured boats made entirely of paper. The key trick was to use a single sheet of paper for the outer hull skin so that no seams existed. I believe they used varnish for waterproofing. Also the paper was molded to allow for a keel rib and gunwale ribs.
Waters came up with the concept in 1867. In 1874 on of his canoes made the trip from Troy, NY down the Eastern coast to Florida.
Interestingly, he also used to technique to build domes for observatories. RPI, West Point, Beloit, Columbia, and Brooklyn Polytechnic all had such domes. Syracuse University was about to get one when Waters accidently set fire to it while working with a torch, burning down his factory and ending his paper boat building business.
