Home Boat Building - Lofting Or Full Sized Plans?

I often get posed the question, "Do your plans come(CAD.) This revolution in the boat designer's world
full sized or do you need to loft them?" I have toallowed the naval architect to use an infinitely large
truthfully answer, neither, which often confusespiece of paper on which to design his boat full-size.
people because they believe home built wooden boatSome of the early versions of AutoCAD came with a
plans are one or the other. In these days offull scale drawing of the solar system with all of the
computer aided design (CAD) drafting, no longer is itplanets and moons. It was 93 million miles from the
necessary to loft boat plans, because the computerearth to the sun! It gave you an appreciation of how
actually does this for the boat designer. What thishuge the solar system actually is. On the other hand,
means to the boat builder, is that all they need to doI have offset likes one millionth of an inch and was
is measure and mark, not loft.able to zoom in until the two lines appeared on
Lofting is a process whereby the boat is actuallyopposite sides of the computer screen.
drawn full sized to determine the exact sizes of theSo, no, you don't need to loft designs properly
frames and components. Back when boat plans weredesigned on CAD, and no there is no reason to need
drawn by hand in smaller scale, it was impossible tofull sized plans or patterns, so long as you select
draw them accurately enough to ensure the finishedmodern plans by designers who use modern
boat had "fair" curves, that is to say, curves thattechnology to design their boats. All plans from Spira
smoothly transitioned from one part of the hull toInternational are computer generated for accuracy
the other. In the old days, a table of offsets or aand pre-lofted in the computer. If you have selected
half hull model was used to lay out several key pointsplans from another designer, ask before you buy,
on the hull, and a long flexible piece of wood, called a"Are these pre-lofted or do they come full sized?" If
spline was used to create a fair curve. From thisneither, then you have a big job ahead of you and
full-sized drawing, measurements were taken toyou better check a few books out of the library so
determine the exact sizes of the framing elements.that you can learn to loft.
Enter the computer and Computer Aided Drafting