Simulate
Understand your boat before you sail it
Simulate is our sail and boat dynamics engine. It models how a real rig responds to wind—computing sail shape, boat speed, heel, and balance from the physics up. Instead of relying on generic polar tables, Simulate builds a performance picture specific to your boat, your sails, and the conditions you’re sailing in.
How It Works
You describe your boat—hull dimensions, rig geometry, sail plan—and Simulate does the rest. Given a wind speed and angle, the engine figures out what shape each sail actually takes under load, how much drive and side force that produces, and how the boat responds: how fast it goes, how far it heels, and how much it slips sideways.
The result is a complete picture of boat performance that updates with every change in conditions. It’s the kind of insight that used to require a tow tank and a wind tunnel, available on your phone.
Capabilities
Sail Shape Modeling
Simulate how sails deform under load. The engine computes the actual shape a sail takes in a given wind, accounting for the cut of the cloth, the rig tension, and the trim you set.
Boat Dynamics
Model the full boat response: heel, leeway, rudder balance, and speed through the water. Understand how your boat behaves in different conditions before you leave the dock.
Real Conditions
Feed in actual wind speed and direction, and see how your specific boat and rig will perform. Results reflect physics, not rules of thumb.
Performance Prediction
Generate polar diagrams and speed predictions for any point of sail. Know your boat's potential so you can plan routes with realistic time estimates.
Built Into Leeway
Simulate powers the routing and performance features in Leeway, our nautical navigation app. When Leeway plans a course, it uses Simulate to account for how your actual boat handles the forecasted wind and current—so the route it suggests is one you can realistically sail.