These plans are very adaptable and allow you to build a boat to suit your needs to a tee. use the huck finn plans to build pontoons from 12′ to 28′ lengths with 8′ beam. except for the 12′ huck finn, all units come with flaring bowed pontoons with sharp entry stems for least resistance.. Plywood boat plans. if you are looking for a way to build an inexpensive boat you should definitely consider plywood boat plans. using plywood is one of the best ways in which to build a fishing boat at a very affordable price. plywood is a preferred material for building boats for a number of reasons.. Once the plywood is flexible, apply one piece to each side of the pontoon with the 1 1/4-inch screws. make sure the plywood is flush with the top and bottom edges of the 3/4-inch plywood. it can hang over a bit, but should not be too short..