Hi


anyone know how this is edited ?
(ie which software can provide angle to wind??)


cheers

sean

I think that was done in GPSAR-Pro.

From memory, the program can make an estimate of wind direction by analysing the tracks. It is not always correct, depending on the pattern of your sailing, but you can manually set the wind direction as well so you can see your approximate sailing angles.

Of course, this is not always correct either if the wind is shifting a lot.

GPSAR-Pro has some very unique and powerful tools in it.

Here is an example of a speed run. The wind angle and wind strength are just educated guesses. I assume my best speed was at 130 degrees off the wind and in 30 knots of true wind for this example. Wind angle could have been less by up to 5 degrees and wind strength could have been slightly lower by a couple of knots, but that has to be pretty close.

Note that, with these assumptions, the apparent wind is at an angle 45 degrees off the bow and at around 85 degrees to the true wind!

If I decrease the true wind speed to 25 knots, the apparent wind angle is 30 degrees off the nose!

If I increase the true wind speed, the angle becomes a lot higher (numerically).

With that in mind, is it any wonder we go faster in stronger winds and broader angles, where more of the resultant force is in the direction of travel.

There has been a big gain in equipment efficiency in recent years where sailors have been able to do 40 knot speeds in less wind with bigger sails, which must mean tighter apparent wind angles, higher apparent wind, and more drag to overcome. But ultimately, the fastest speeds are set in the strongest winds we can find, at the broadest angle we can sail and still have flat water.

Or you can play the low drag game and go for really flat (weedy?) water, with smaller sails and fins and use the apparent wind to go broader to the true wind.

I think that going for speed is a lot more tactical than most people realise, and to me, therein lies the challenge and enjoyment.

And this is why GPS speed sailing is all about the 'bearaway', and the skill of finding gusts and the perfect angles. Fixed courses and gated courses are not so much about tactical skills, and more about the size of the sailor and optimising his gear for efficiency, which usually means most dollars and biggest guy wins. Not much fun in that unless you are the biggest guy with the most of the latest gear.

thanks Andrew !

Yep that's GPSAR. I use it a lot.
Seems that if you do some runs hard upwind on both tacks, calibration in the analysis program is fairly accurate re angle to wind.
Always a bit off with an asymmetrical fin on a speed course.
Lots of interesting data to be had from GPSAR.
You do need a GPS though, so no good for PWA pros, according to another post here.
Never have been able to understand people who don't want information.
The man with the most info wins.

I have been thinking about a technical aspect of measuring wind direction on our windsurfing gear.
Obviously, the relative angle measured while we are sailing 35 knots and wind is 25 knots is completely different to stationary measurements. But this is the whole beauty of our personal individual measurement in high-speed sailing.
This individual, relative angle to the wind tell us much more; how good our gear is working, precisely to the wind. Allow for perfect tuning to achieve max performance.
The problem may be that angle meter for our purpose doesn't exist yet. All mechanical devices are clumsy and prone to damage or clogged/ affected by water and sand.
So I invented quickly one that works for us. It is simply few whistle like tubes installed on the top of the mast, at different angles. Each tube is now equipped with the own microphone. If types/ whistles are in different vertical and horizontal angles we could now have the complete 3D picture of the passing relative air flow. Simple smartphone android processor/applet could now calculate exactly wind speed airflow. After initial calibration No moving parts in our anemometer, nothing to break down. Simple and easy.I imagine that simple 3D star like / ball design of small tube that ends with a microphone at one end will be sufficient to electronically calculate airflow just from noise.

Or maybe just set up an electronic recording wind vane and anemometer on the beach (or a floating buoy) and use that data in GPSAR-Pro?

Select to expand quote

Macroscien said..
I have been thinking about a technical aspect of measuring wind direction on our windsurfing gear.
Obviously, the relative angle measured while we are sailing 35 knots and wind is 25 knots is completely different to stationary measurements. But this is the whole beauty of our personal individual measurement in high-speed sailing.
This individual, relative angle to the wind tell us much more; how good our gear is working, precisely to the wind. Allow for perfect tuning to achieve max performance.
The problem may be that angle meter for our purpose doesn't exist yet. All mechanical devices are clumsy and prone to damage or clogged/ affected by water and sand.
So I invented quickly one that works for us. It is simply few whistle like tubes installed on the top of the mast, at different angles. Each tube is now equipped with the own microphone. If types/ whistles are in different vertical and horizontal angles we could now have the complete 3D picture of the passing relative air flow. Simple smartphone android processor/applet could now calculate exactly wind speed airflow. After initial calibration No moving parts in our anemometer, nothing to break down. Simple and easy.I imagine that simple 3D star like / ball design of small tube that ends with a microphone at one end will be sufficient to electronically calculate airflow just from noise.

Funny that you mention noise. I unconsciously use noise in both ears to determine apparent wind angle. If you point your head at the apparent wind it sounds the same in both ears, even with a helmet on you can feel it on your face.