Vintage 1971 USPS Course Plotter Navigation Tool with Original Instructions Vintage USPS Course Plotter navigation tool designed for measuring courses and bearings on charts. This translucent green plotter features a protractor scale and parallel lines, making it an essential instrument for maritime or aviation plotting. It includes the original paper sleeve which contains detailed instructions for use, covering measuring bearings, drawing courses, and celestial lines of position. A great collectible or functional tool for traditional navigation enthusiasts. Copyright 1971. Staining on envelopes. #Vintage #Travel