Just as a matter of intrest what is your slowest speed in the mid corner of any given alpha and the alpha speed?
I guess you could be slightly slower on the straight and keep the speed through the turn and still be on par with being faster on the straight and pulling too much handbrake on in the corner.

25 alpha 16 min 30 max, 24 alpha min can go down to 12

and min isn't mid corner it's at the exit just before power on

Lao Shi and I did a big stint of alpha sessions about a year ago and consistently found that min speeds did not play as vital a role as the entry and exit speeds.

For example some of my slowest corner speeds were as low as 11 but resulted in 24 alphas. To me it's all about how quickly you can get OFF and then back ON the power.

My alpha record, i was very lucky to get back in the 50m radius, i just followed the edge of the circle...So a near perfect jibe, among a few of the others i did that day. My out speed were identical to my in speeds.

As Decrepit and Snake said, and Izaac has proven so elegantly, out-speed is the key to a really fast Alpha.
Getting out with max accelleration back to top speed ASAP is what makes all the difference. Oh.... and still clipping the proximity circle.

My highest 'low' speed in a good Alpha was 19 knots from memory. Well that was according to the GPS 'trackpoints', but I don't really believe it. And it was not my fastest Alpha anyhow. Fastest ones had slow points closer to 14-15 knots, not sure without running the files again, and I don't know that those figures are all that reliable anyhow.

great reply Izaak, those numbers are very interesting.

So the next part of this discussion is how to go 30+ across the wind within 250m of your gybe?
Personally, a flatter less downhauled sail seems to help and a bigger board to accelerate faster.
Interested to hear from the gurus.

Select to expand quote

WindsurfingWA said...

So the next part of this discussion is how to go 30+ across the wind within 250m of your gybe?

More wind perhaps...

The best I can do square reaching is around 32-34 knots in quite windy conditions. At this speed on flat water of have reached a point where it is quite difficult to turn in my iSonic 87. The rail does not want to sink!
I tried a Carbon Art CA50 and it turned in easily at 32-33 knots but lost speed too fast in the gybe and was slower to accelerate.
At Lake George, during my best 1 hour, I was able to consistently pull 30-31 knots square across the wind in 30 knots with a 5m sail on the IS50 and Lessacher 22cm speed rake 30. Nice flat water though....
The gybes were quite fast but when I looked at the tracks, most were a bit too wide to hit the proximity circle because I was not really trying to do that. I was rigged for low drag and speed square and had a smallish fin so accelleration out of the Gybes was also not as good as if I was rigged larger or fuller.
The best Alphas I have done were 30-32 knots on the in run, a nice fully powered gybe and as I came out I got a really good gust to shoot me back to 28-29 knots as fast as possible. If you are lucky enough to get a slight wind shift as you turn so the out run is slightly broader, so much the better.

As you can see, i was trying to run dead square to the wind each way, allowing me to do identical in and out speeds.. All my alphas were done on my JP Speed 45, i know the board so well, that i can use it like my slalom board.

Select to expand quote

izaak said...

As you can see, i was trying to run dead square to the wind each way, allowing me to do identical in and out speeds.. All my alphas were done on my JP Speed 45, i know the board so well, that i can use it like my slalom board.

Hey Izaac, can you zoom in on the speed graph at the bottom for your top alpha and post a screen shot please?
Use "view>zoom to result" Like this:

An Alpha from a 1 hour run the day before my record 1 hour - pretty sure this one was on the CA40 with assy fin:

Ok, here is my dream Alpha. This one was during my record 1 hour. I got everything right except for one thing. 85m proximity circle! My only excuse is that for 1 hour this is faster.
That's how it should look though, but tighter!

It appears one ingredient of an outstanding alpha is to clip the 50 m circle with no more than a couple of mm to spare. How do you do it? What navigation tricks do you use? When I try for alphas on trackless Lake Illawarra most are way too wide. And then my best for the day often looks like that other alpha, the Greek alpha.

I've tried siting my wake against a mountain on the way in, doesn't seem to work. Sometimes your ingoing wake is still visible, but if it's a good gust, it's not. What's the trick?

Luck!! and doing as many alphas as possible. Eventually you should be able to judge the distance quite well.

Select to expand quote

izaak said...

Luck!! and doing as many alphas as possible. Eventually you should be able to judge the distance quite well.

Yes, thanks Izaak.

A mate once said to me " Ian, I hope you never leave Canberra, because if you do I'll be the worst navigator in Canberra "

Well I did and he is.

I was pretty happy with this one at Elwood max speed only 23.3 and still a 20 knot Alpha, in the bay its more about timing between the swell so sometimes the arc is not so smooth.

Select to expand quote

Ian K said...

It appears one ingredient of an outstanding alpha is to clip the 50 m circle with no more than a couple of mm to spare. How do you do it? What navigation tricks do you use? When I try for alphas on trackless Lake Illawarra most are way too wide. And then my best for the day often looks like that other alpha, the Greek alpha.

I've tried siting my wake against a mountain on the way in, doesn't seem to work. Sometimes your ingoing wake is still visible, but if it's a good gust, it's not. What's the trick?

One trick I've used:
1) Find a buoy or similar that is 200m or so away from where you gybe. On your inbound leg, pass around 40m upwind of it. Do your gybe, then aim to get within 5m downwind of the buoy.

It helps if you measure out 40 metres on the ground beforehand so you know how far that is.

The crab munchers have been known to set up two buoys 50m apart for exactly this purpose

This is all good information. It seems that an alpha is only half what I thought it was. I assumed it was the full alpha shape.

So is it 250m approx from the centre of the circle to the corner of the gybe?

Select to expand quote

Jman said...

I was pretty happy with this one at Elwood max speed only 23.3 and still a 20 knot Alpha, in the bay its more about timing between the swell so sometimes the arc is not so smooth.

That's pretty impressive!

Select to expand quote

izaak said...

Yep, that's how it should be done!

Select to expand quote

Jman said...

I was pretty happy with this one at Elwood max speed only 23.3 and still a 20 knot Alpha, in the bay its more about timing between the swell so sometimes the arc is not so smooth.

Excellent Alpha on open water!

Select to expand quote

da vecta said...

This is all good information. It seems that an alpha is only half what I thought it was. I assumed it was the full alpha shape.

So is it 250m approx from the centre of the circle to the corner of the gybe?

total distance must be 500m or less, seperation between start and end points 50m or less.

so not sure what you mean by centre of circle and corner of gybe. Ideally it looks something like a "U"

Select to expand quote

Ian K said...

It appears one ingredient of an outstanding alpha is to clip the 50 m circle with no more than a couple of mm to spare. How do you do it? What navigation tricks do you use? When I try for alphas on trackless Lake Illawarra most are way too wide. And then my best for the day often looks like that other alpha, the Greek alpha.

I've tried siting my wake against a mountain on the way in, doesn't seem to work. Sometimes your ingoing wake is still visible, but if it's a good gust, it's not. What's the trick?

Hi Ian, You are on the right track. At Sandy on an Easterly I start my run next to one of those big green buoys. On the return I use it to try to judge the Proximity. After a while it is not too hard to judge 45-50 m pretty well.

On the SW bank it is not quite so easy without a convenient buoy so I try to run in to the bank on a tight pinch and then go square for 200m flat stick. On the return I try to judge 45m from the bank but if I am slightly wide, at least I will come close to the in track after 200-250m.

At lake George, in the middle of a big lake without any obvious markers, the best bet is to sight on the other side of the lake. After a few runs back and forth you should be able to work out sighting marks on each side to aim for so you know your are square. The ripples on the water can help here as well as the feel of you rig and speed. I wear my GPS where I can see it. After a few runs you will soon get a pretty good feel for what is dead square. Then it is just a matter of pulling the smoothest tight gybe you can and hammering back as square is possible. One other thing that helps at LG is the wake track you tend to leave in the really saline water. On most runs it stays visible long enough to get another useful cue from.

Hope this helps.

"The older I get, the better I was"

Thanks for this thread, I think I finally get how to improve my Alpha

Cheers Russ

Yes a few clues there for featureless lakes Andrew. The landmarks then will have to be fairly distant or you'll have to not roam too far off your beaten track. I suppose you also need to standardise your gybe radius at 50 metres. That's a fairly tight gybe at around 30 knots. Variable gybes to 80 metres wide will need too much upwind, and tricky landmark geometry.

Thanks, I'll put it to use when the westerlies return. It's a long time since I pb'd an alpha.