Spira international wooden boat plans. following are the stock plans available for the various types of boats, separated into the different categories.. Scroll down this page for many more plans. this a page of links to some favourite free boat plans at intheboatshed.net. they’ve been chosen because they are derived. Free plans: absolutely free plans (links to free online boat plans) ariawood boat works (plywood punts, jonboats and one-sheet boats) architectura navalis mercatoria.