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.  altair industries driftboat plans altair offers complete plans and a construction guide for a 16′ mckenzie river drift boat. (added: 2-dec-2003 hits: 44606) my. Share your love of wooden boats and the river lifestyle. by becoming a member you agree to use this network primarily for wooden boat info..