If you’ve just cruised to the Caribbean and are about to sail home from America, consider this: plotting a great circle course (the shortest way across the outside of a sphere) used to involve special charts or mathematics. Not any more. You can tell a decent chart plotter how you’d like your courses served up. Here are the great circle and rhumb line courses from New York to Bishop Rock. The great circle is not only 30 miles shorter, it runs right along the coast, so you can pop in to Lunenberg, Nova Scotia, for a nice cod supper to break the trip. Of course, a sailing boat is driven by the wind, so you won’t stay on the great circle but, with electronics, determining a new one every day from where you happen to be is as easy as plotting a rhumb line.