Navigational Douglas Protractor 5" x 5"

Navigational Douglas Protractor

Navigational Protractor also known as a Navigation Square Protractor or Douglas Navigational Protractor for Air and Sea 5" x 5" for measuring on charts, determining bearings, or to use as a parallel rule. Navigation protractor 360° marked in 1° intervals. Sometimes referred to as a Douglas protractor, the 5" Square Protractor is best suited for rapid plotting of courses and bearings in a confined space. Notations can be easily made directly on matte plastic surface with pencil. A cursory inspection of this protractor will show its many advantages over other forms, especially to the seaman, for in using it dividers and parallel rulers are not needed.
Size 5" x 5" x .030"