This bi-rola chart protractor turns the tedious task of plotting into child’s play. It virtually eliminates the need for other devices except a pencil. Plotting a course is as simple as laying the protractor along your course line and aligning the compass disk. Laying off courses,bearings, distances..
Multi-purpose Plotting tool, ''Compute-a-course'' is a compact, multi-purpose plotting tool. Ideal for general boating or commercial use. It can be used for position fixing, course plotting and distance measurements with the included scales. Using the log scale on the instructions, time/distance cal..
Very easy development path. First you need to align the course with the arrow on the ruler. Then you may count the degrees based on the reading of the compass plate. Very preciseDimensions: L36.5cm x W13.5cm..