Learn the physics of sailing
Short, practical guides to what the wind is really doing to your sail. Every guide has "Try it" buttons that open the simulator already set up to show the idea.
How a sail works: lift, suction and stallWhy a curved sail pulls a boat forward, and what happens when the air can no longer follow it.7 min readApparent wind explainedWhy the wind you feel on a moving boat is not the wind that is blowing, and why it matters for trim.7 min readReading telltales and trimming the sailThe little yarns on a sail show exactly what the air is doing. Here is how to read them.7 min readWhen to reef: heel, drag and speedWhy too much sail makes a boat slower, not faster, once the wind builds.8 min readQuick referenceFlow states of a sail at a glance, and how a monohull and a catamaran differ.Reference tablesSailing termsPlain-English definitions of every sailing and physics term used on this site.Glossary
New to the simulator? Open it, pick a boat, and move the wind and trim sliders. The guides will make more sense once you have seen the airflow move.