VECTORMASTER
Weems & Plath

Easily compute vector solutions to current sailing, true and apparent wind, and relative motion problems with this miniature (7 inch square) plotting board. Soft pencil lines on the rotatable grid are connected with new vectors aligned by the rotatable grommet, and are easily erased later. The reverse side is a circular slide rule annotated for time speed distance problems and has printed instructions for using both sides. An instruction booklet is included with this well-made, advanced navigation tool. SW 0.5 lb.