This is one of the quickest and easiest plotters to use. It consists of a 12" plotter mounted on a roller. Courses and parallel lines are transferred and kept parallel by means of two rollers which are mounted on a slide axis. Included are a semi-circular protractor for measuring courses and bearings against a meridian on the chart and two quarter circle protractors for measuring courses and bearings against a parallel of latitude. It also has distance scales at 1:20,000, 1:40,000, and 1:80,000 to fit the N.O.S. coast and Harbor charts, and also an inch scale.