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. Spira international wooden boat plans. following are the stock plans available for the various types of boats, separated into the different categories.. All power boats 16′ long and under. tech support. the best technical support: we will help you succeed! all our plans and kits come with full technical support..