Davis Charting Kit - Complete 
The Davis Charting Kit comes with one-arm protractor, course plotter, protractor triangle, parallel rules, dividers, pencil and instruction booklet. It's all organized in a 5-3/4" x 16-1/4" (146 mm x 413 mm) heavy gauge plastic storage case. An excellent gift idea for cruisers and racers alike.
Quick Guide (pdf)