How do sail boats actually work?

Question

The sails always seems to be somewhat parallel to the direction of the boat, but if the wind is blowing sideways, should that push the boat off course?

In: 9

Answer 1

Sails act like a wing most of the time. The air moving over them generates lift*. Boats have a keel or a dagger/centreboard that stops them drifting sideways to an extent, but they do still drift slightly.

*If a boat is heading away from the wind, the primary mechanism of propulsion may just be the wind pushing the sail.

Answer 2

Sails act like a wing most of the time. The air moving over them generates lift*. Boats have a keel or a dagger/centreboard that stops them drifting sideways to an extent, but they do still drift slightly.

*If a boat is heading away from the wind, the primary mechanism of propulsion may just be the wind pushing the sail.