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. View our collection of diy sailboat plans that feature boat design for sailboats of all types! we have sail boat plans for yachts, day sailers, and more.. Share this: free model tugboat plans for klimek tugboat klimek tugboat plans are perfect for model ship building hobby. they are specially prepared for model building..