The Blundell Harling Portland Plotter and Dividers Kit is THE essential piece of navigation equipment for every sailor. Set off on the right course with this simple to use navigation aid and divider set! Comprises of a Portland course plotter and 7" brass single handed dividers. Ideal for evening classes. We sell literally hundreds of these a year as they really are the best - easy to use, easy to clean and a the best value kit around.