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 designs that are simple to build, rugged and seaworthy.. “building boats from glen-l plans is simple and straight forward…i honestly have never run into a problem, unless it was of my own making. follow glen-l’s plans and you can’t go wrong.” dr. norman cove, bahamas “boat building is one of the few pursuits where utilization of the end product is as rewarding as its […]. Why build an aluminum boat? for things that go bump in the night. for ease of construction. for longevity. for good resale value. for the benefit of being able to create a custom design and build it economically, without the huge penalty of having to build a mold first, as with fiberglass..