Curve copying tool

There are many curves in a boat that need to be measured, and then have a board cut to fit that curve. One method of finding the profile of that curve is to make a "curve copying tool" with a stick and pencil. First you fix a big piece of cardboard perpendicular to the curve you want to measure, then you move the stick along the curve, and the pencil draws the curve onto the cardboard. You can then use this as a template to cut out your piece of wood.