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It's the wind just as you launch that was apparently there rigging up but is now all but gone.
while Sausage has clearly taken top podium position...
It is simply where the wind appears to be coming from.
So combination of board speed/direction and wind speed/direction.
EG if sailing on a reach and wind drops to nil, for the brief moment you remain planing your apparent wind is totally head on
EG2 - 30kn wind and you are sailing on a reach then suddenly stop dead, the apparent wind moves from say 45 deg to 90deg as you have zero board speed.
rather simple I thought...?
I think the easy answer is the it's the wind you feel on your face when moving faster than actual wind speed. But there have been a few hazy nights/years since sailing school so could be completely wrong and need correcting .
^^^ you don't need to be moving faster than the wind. On a reach as soon as you move forwards at 5kn or 1kn, the wind that was coming from behind you swings to the front (apparently). Faster you go, the more it appears to be coming from the front.
That's all you need to know.
Sorry. I thought that Wikipedia article was pretty clear.
Scenario 1:
I am stood stationary on the beach.
The wind is blowing 20 knots from the north.
The true wind speed is 20 knots.
The apparent wind is 20 knots from the north.
Scenario 2:
I am travelling at 20 knots EAST (i.e. at 90 degrees to the wind).
The wind is blowing 20 knots from the north.
The true wind speed is 20 knots.
The apparent wind is 28 knots from the NORTH EAST.
This means that the wind APPEARS to be blowing from 45 degrees to my direction of travel, instead of 90 degrees to my direction of travel.
This means that as you go faster and faster, you have to bear off more and more from the wind in order to keep the wind in your sail...
Wanna play further?http://www.sailingcourse.com/keelboat/true_wind_calculator.htm
I'm not entirely happy with the word "appears". I know that's what it's called, but relative to the moving object, it's very real.
It is the actual speed and direction of the wind relative to the moving object, and if your using wind power, it's what you have to play with, not the wind relative to something stationery.
Last year was my final year of school and for one of my subjects I did a study of the physics of lift in relation to planes and sailing. Thought I might as well share the page about thrust and apparent wind seeing as it is relevant.
^It's been a long time since I did vectors and physics at school...in fact a long long long time ago but if I'm travelling north at 100km an hour with a 20km tail wind (southerly) isn't the apparent wind 80km from the north, not 120km as per the above school text book????? Don't see many planes taking off with a tail wind!
Maybe they mean the wind is coming directly from the direction you're travelling in - not well worded
Oh wow, glad the assessors didn't notice that; you are indeed correct. In the brackets it should be "(assuming you are travelling against the wind)" or something to that effect. And I agree, the wording is a bit awkward. Cheers :)
I find the vector picture the easiest to understand. Note that if your speed and the wind speed are drawn in proportion, you get the exact apparent wind by measuring that side. Try with different wind angles, board speed etc, you will find why it's so important to bear off a lot to increase your speed
Makes sense. You are travelling perpendicular to the wind. Wind is 20kts. You're travelling at 20kts. Apparent wind is 28kts. You should go exponentially faster though right? Guess not, because its only "apparent" wind (well 8kts of it), not real wind.
Now I'm confused.
It is real - it is the collision speed of the air molecules you are hitting.
(Leaving the term "exponentially" out of this...)
As such, the faster you go, the faster you can go (to a certain extent limited by a massive heap of other physics like drag, and the fact that you constantly need to bear away as you get faster which has limits).
Sounds crazy right?
This is why the Sandy Point speed run works so well.
You start off running at approx 90 degrees to the wind. As you get faster the apparent wind moves forward and increases. This means that you can go faster, but not pointing the same direction - you need to bear away.
If you look at the end of the speed run on Google Maps you're no longer travelling south-east... instead you're travelling east but still sheeted right in.
Out of interest the Americas Cup 72'ers were so efficient dead down wind that they effectively created a head wind ......apparently 
. Yes there's no excuse for my tardy explanation even though I watched every single AC race and understood the dynamics of sailing the downwind leg.
