Originally Posted by flysci
For a simple shelf this seems the best way. I've seen it done with dividers set to a width just wider than the widest gap, then drag it along following the curve with one point, and scribe the shelf with the other - best if divider has a pencil for one leg.
As an alternative to dividers, I use the plastic top from margarine tub or peanuts can, or whatever is available. Place the top at close intervals against the hull, and draw the perimeter circles on the template. Overlap the circles as closely as the hull shape requires. This also works when you are transferring compound or "S" shapes, such as turn of the bilge
areas on bulkheads. Lay the template on your stock, place top on the template circles, and transfer remainder of the circle back to the stock. Connect the arcs and you have your shape. This is how I did it when replacing all the bulkheads in Bluestocking. Scribed the circles on the old bulkheads, cut them away from the hull with recip saw, and used them as the templates.