Blundell Harling Professional Navigational :
Well if you’re a purist then this is the product for you its Blundell Harling’s Professional Plotting tool. Boasting loads of features
including the ability to cover large admiralty charts with Captain Fields pattern markings and pencil guide holes for true location precision and the ability to set magnetic deviation and variation on the plotter. It comes at a hefty £39.99
but a good tool and worth every penny.