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. While we are primarily custom wooden boat builders, we have decided to also make some of our designs available for amateur construction. we have drawn up detailed. High speed welding t tops aren’t like cheesy bolt together t tops you can buy at marine retail stores. after about a year those tops will start to corrode and the.