The Portland Course Plotter Kit. Used worldwide by practical and shore based instructors for accurate course plotting, Yachtmaster and Dayskipper courses Plotter with bright blue directional arrow prevents accidental reciprocal bearings Edges are graduated for tide and boat speed Base has a fixed grid so it is easy to plot latitude from your GPS system Kit includes a 7" Single Handed Divider Comprehensive instructions included The most popular small boat navigation kit as used by the RYA for course plotting.