How do sails really create thrust?

Beginner sailing texts compare sails to the wings (airfoils) of an airplane and repeat the debunked misconception that low pressure on the top of the wing and high pressure on the bottom of the wing creates lift. This is not the whole story. Most wings (airfoils) are in fact asymmetrical, BUT you can fly a plane inverted (upside down) and the wing will still generate gravity defying lift.

Also on plane wings you have something called angle of attack AOA, that being the angle of the chord of the wing (a line from the leading edge to the trailing edge) relative to the angle of the air flow If AOA exceeds 15-20 degrees the wing stalls and ceases to produce lift.

So in my elementary sailing texts, the AOA on the sail (wind direction relative to chord of sail) is drawn at 60 degrees or so. I understand that the boat is moving forward, so the RELATIVE wind and the AOA is somewhat less. But the sail still looks like a ‘stalled airfoil’ to me.

So how does a sail produce thrust? (I understand vectors).

I want to resolve this in my own mind before I get to my first sailing classroom session (in June) so that I can keep my mouth shut and not contradict the teacher when she repeats the standard explanation.

Edit: If a student pilot were to ask me how a wing produces lift, I would tell him “Magic”, then I’d make sure he understood the cases where a high AOA produces a stall, how to recognize that a stall is happening, and how to return to normal unstalled flight. That’s all that really matters in a plane.

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