The Weems and Plath Three-Arm Protractor is a professional plotting aid whose heavy-duty, crystal-clear acrylic construction makes it a satisfyingly efficient and straightforward tool to use.

The arms are rigid enough to trace a bearing line and they can be used to position and chart from three identifiable shore, landmark or buoy locations just by measuring the angles on the protractor and locating your position on the chart.

The moveable arms of the Weems and Plath Three-Arm Protractor have a Vernier scale for even more precise measurements.

This protractor is very convenient for laying out course lines and plotting fixes from a number of fixed positions obtained using a sextant or a hand-bearing compass.

The transparent nature of the protractor’s material means you can lay it over a chart and still see the chart underneath.

The middle arm of the protractor is a fixed one while the other two can be adjusted and there is a hole in the centre of the compass rose to let you mark your position accurately.

• Dimensions: 6 x 21 inches
• Weight: 5 oz