We have power boat building designs of all types such as power cats, cruisers, and more. view jon boat deck plans & boat cabin plans for more details.. Boden boat plans professionally designed ocean proven. thousands of boden designs have been built from the stock plans available. many have completed world circum. Welcome to spira international home-built boat plans. spira international offers a wide variety of different power, rowing, and sailing skiffs, dories, and other boat.