Chances are if you have spent most of your life cruising around on a sailboat, you know a bit about what makes sails work. Foils, canards and wings, however, may mystify you. We’ve tried to simplify the principles for those of you who have a phobia for math, physics and applied sciences. What follows is enough to make you dangerous. Leave the applications of these principals to experts such as Morrelli & Melvin, who have rocket scientists, naval architects and engineers on staff. Bernouilli’s Theorem is also known as the longer path explanation. A sail is an airfoil.