Sailing & Tacking Simulator
A top-down sailing course with a live wind field that shifts and gusts. Steer your boat with the arrow keys or point-and-click, and the physics answers with the real geometry of sailing: you cannot aim at the wind, speed depends on your angle to it through the boat’s polar diagram, and getting upwind means zig-zagging through tacks that each cost you speed. The apparent-wind vector, laylines to the mark and your velocity-made-good are drawn live, and a route optimizer races beside you, showing what perfect play through the same wind would look like. Beat the router to the windward mark — catch a favourable shift it reacted to late — and you have understood racing tactics.
Runs 100% in your browser — simulations are computed locally on your device.
Read the full guide to this tool
Notes
- The polar diagram is the boat’s performance fingerprint: speed as a function of wind angle, fastest on a beam-to-broad reach, dead slow straight up- and downwind — the reason both beats and runs are sailed in zig-zags.
- Velocity made good (VMG) is the number that matters upwind: not your speed, but its component toward the mark. Pointing higher looks better and is often slower.
- Wind shifts decide races: tacking onto the lifted side of an oscillating breeze gains distance every cycle — the router exploits this, and so should you.
- Runs 100% in your browser — simulations are computed locally on your device.
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