Buy the Portland plotter and single handed 7" divider as a kit, it is more economical. The Portland Course Plotter Kit, used worldwide by practical and shore based instructors.
• 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.
• Includes a 7" Single Handed Divider.
• Comprehensive instructions included.