A special jig was designed to prepare an accurate graphical record of a two-bladed airplane propeller which was used in Canada to propel one of the world's first high performance hydrofoils, in 1919. Such propellers are complex-shaped objects with twisted planes in space. The measuring and drawing jig, which was designed by the author, is simple to make in any conservation workshop. It can be adapted to the recording of other complex shapes as well. -- AATA