4 ms·

This person is not a sailor. Sailing orthogonal to the wind, a "beam reach", is the fastest point of sail due to the lift of the sail.

jacquesm 3y ago
What's interesting is that if you manage to exceed the hull speed doing that you'll end up surfing on your own bow wave!
Zanni 3y ago
I knew someone would make this comment. I love HN for this kind of pedantry when it's specific, accurate and doesn't dismiss the entire article for one inaccurate analogy.
- jws 3y ago
  Also, "broad reach" would like a word with lfnoise. (It's complicated.) https://physics.stackexchange.com/questions/186515/why-is-a-beam-reach-the-fastest-point-of-sail-on-modern-sailboats https://physics.stackexchange.com/questions/186515/why-is-a-...
  - bmm6o 3y ago
    The polar diagram shown there is what should replace the ellipse in TFA. It's far more complicated than a simple geometric shape since it has to account for such practicalities as sail inventory.
- lfnoise 3y ago
  I also knew that someone was going to comment the the beam reach was not necessarily the fastest.
deleted 3y ago
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sepen77 3y ago
I didn't know anything about sailing, but your one comment made me search up point of sail and now you've opened my eyes to something that was a mystery to me for all my life -- how sailboats can "course made good" against the wind. Thank you.. this stuff is amazing, and sailing is an incredible science!
joelthelion 3y ago
What does the "circle" look like with correct assumptions?
mnw21cam 3y ago
A beam reach isn't necessarily the fastest point of sail. It depends on the boat, the efficiency (lift/drag ratio) of the sail, and the efficiency of the centreboard/keel (again, lift/drag ratio), but a reach of some kind is likely to be the fastest - it just won't be exactly perpendicular to the true wind direction. It'll also vary with the wind speed, wave height, weight distribution, etc.

jacquesm 3y ago

What's interesting is that if you manage to exceed the hull speed doing that you'll end up surfing on your own bow wave!

Zanni 3y ago

I knew someone would make this comment. I love HN for this kind of pedantry when it's specific, accurate and doesn't dismiss the entire article for one inaccurate analogy.

jws 3y ago
Also, "broad reach" would like a word with lfnoise. (It's complicated.) https://physics.stackexchange.com/questions/186515/why-is-a-beam-reach-the-fastest-point-of-sail-on-modern-sailboats https://physics.stackexchange.com/questions/186515/why-is-a-...
- bmm6o 3y ago
  The polar diagram shown there is what should replace the ellipse in TFA. It's far more complicated than a simple geometric shape since it has to account for such practicalities as sail inventory.
lfnoise 3y ago
I also knew that someone was going to comment the the beam reach was not necessarily the fastest.

deleted 3y ago

[deleted]

sepen77 3y ago

I didn't know anything about sailing, but your one comment made me search up point of sail and now you've opened my eyes to something that was a mystery to me for all my life -- how sailboats can "course made good" against the wind. Thank you.. this stuff is amazing, and sailing is an incredible science!

joelthelion 3y ago

What does the "circle" look like with correct assumptions?

mnw21cam 3y ago

A beam reach isn't necessarily the fastest point of sail. It depends on the boat, the efficiency (lift/drag ratio) of the sail, and the efficiency of the centreboard/keel (again, lift/drag ratio), but a reach of some kind is likely to be the fastest - it just won't be exactly perpendicular to the true wind direction. It'll also vary with the wind speed, wave height, weight distribution, etc.