You can build a canoe from plywood very easily. What's more it will be a very good canoe and it will cost a small fraction of the price of a commercially made canoe. You can use 1/8 inch door skin for the covering which is quite low cost. You can also use 1/8 inch marine plywood. The latter however is difficult to obtain in many areas. Heavier plywood is difficult to bend to shape but if you are prepared to sand it down thinner so that it will bend and possibly also to steam or soak it you can use 1/4" exterior plywood. This makes for a heavier and strong canoe but entails more building difficulty then 1/8 inch door skin. The door skin should be finished with several coats of urethane varnish to waterproof it. You could alternatively put a layer of fiberglass over the doorskin which will waterproof and strengthen it. You can find this plan and many more interesting DIY plans in my eBay store at: http://stores.shop.ebay.com/Books-Plans-and-Prints-4U