Birch bark from the ground or from a dead tree, scissors, glue.
Find a piece of birch bark and cut into a rectangular shape (ex. 3 by 5 inches). Cut corners slightly and bend in half lengthwise. Bend the bottom right corner (where the bark has bent) over so that one side overlaps the other and glue into place. Repeat on bottom left corner. While holding the ends, push inward slightly to open up the middle more. This should add stability. Trim the top half for a more “canoe” shape.
“You may have to glue a small stick to the bottom to stabilize.”