Jamie, they would do like Mullet said about the fire. They would build up a big thick ring of mud, and clay, around the tree, and then start a fire around the base, and keep it burning, till it burned far enough through to topple the tree. Once they determined the bottom, and top, and started to shape it, they would drill holes, about 3/4's to and inch deep, all along the bottom. Then when they burned, and scraped the hull out, and came to these holes, they knew not to burn any deeper, and they could keep an even thickness all along the bottom. Then when finished, they would plug the holes, with a stick, and cut it off flush, and it would be water proof, as it swelled. There used to be one at Dubois park, in Jupiter Fla. When I was a kid I was always fascinated by it. It belonged to Bessie Dubois, and it was kept by the house, on saw horses. Not a whole lot of free board. Used to see pictures of Seminoles in them with their whole family in those things. Not much free board, and not much to keep a big ol gator from bumping someone in. Not the most stable looking thing. They would put wet sand, in the middle of the canoe, and build cooking fires in them. Always wanted to build one. Dug out, not cooking fire. That's what the wimin were fer......
Wayne