W&P 116 Heavy duty, nearly unbreakable, flexible crystal clear acrylic construction is the foundation for this simple to use, professional plotting aid. Arms are rigid enough to trace a bearing line. Use to lay out course lines or plot fixes from multiple fixed positions obtained by a sextant or hand bearing compass. Translucent to allow overlay on a chart with full visiblity underneath. Center arm is fixed with two adjustable arms and a hole in the center of the compass rose for marking your position.
Can be used to position and chart from three identifiable shore, landmark or buoy locations. Just measure the angles on the protractor and locate your position on the chart. Wt. 5 oz. Arm length is 15" (38 cm).