I would like to see the 50knot barrier broken first over 500m.Antonie has did 49.09 so what was his peak speed??.

his peak was under 50

50kts is around 25m/sec. So a 2sec peak would be at least 50m...

Hmmmm... you might be onto something there Ian. The accelleration we get when we sail the Easterly speed bank is fantastic as we bear away almost 90 degrees in about 25 meters. But it always seems like there is plenty of load on the fin as we do it. Maybe not as much as there would be if accelerating in a straight line though. I must say also, that the peak speed of those runs is always a few seconds down the track where we are going pretty straight.
Likewise my best peak speeds on the SW course have always been on the part of the course which is virtually straight. However, at those points we are very broad off the wind so there 'feels' like there is less lateral load on the fin.
The situation is a bit like this:
Pick the big squall - sail into course and struggle to keep it together square to the wind without getting lifted off the water, just the right feathering of the sail and weight on the board, this is often the most razors edge part for me - try to get as much power and stability on as you start to get towards the best angle, feels like lots of load on the fin here and a big danger of tail-walking - stance becomes more comfortable as angle and speed improves - now you are at low 40's and wishing for a big gust because you know you can handle it at this angle - a few seconds later you are going pretty well straight and at max speed but now getting into the part of the course where the following chop is quickly building - now you are thinking: 'do I hang on longer with the increasing risk of a crash, or start to back off'. This is the bit where confidence is king and a bit of controlled, aggressive risk-taking can pay off big time! , or result is a world of pain! - when you know you are slowing down, (and I always try to go a few more seconds even when I think I am slowing), it's time for the riskiest part of the run: stopping without crashing! - feet land on the sand and immediately look down at your GPS. - Have another long look to make sure you read it right and start whooping and punching the air!

Is 60 knots possible?

Well in '89 the question was " is 40 knots possible?". I wasn't even 40 then.
Eric Beal and Mal Wright amazed and inspired us all and proved it was.

In 2005, I was well into my 50's and had done 40 knots a few times. The question was now 'is 50 knots possible'?

A few years later Slowie, MVM and Spottie had shown us it was (at least for a couple of seconds). I haven't done a 50 yet but I actually think it might be possible for me on a perfect day.

Is 60 knots possible? Certainly not for me if it's going to take another 15 years (somehow I can't see a 72 kilogram, 75 year old doing 60 knots! ) But, given hindsight, I certainly don't see it as impossible for some skilled and bold young speed knight. After all, in '89 we thought 50 knots was just some ridiculous wild dream!
I am really looking forward to seeing the developments that evolve to make 60 knots on a windsurfer a viable possibility.

Yeah. I dream of holding 30 knots right through the gybe and coming out at 30 knots!
I think the best I have done is a slow trough of just under 20 knots, and most of the best are around 16-18.

Ian K said...

sailquik said...


Likewise my best peak speeds on the SW course have always been on the part of the course which is virtually straight.

Fair enough Andrew, but I suppose it shows that at abnormally high speeds you don't have to be on all that tight a curve for the straight line sailing forces to be shifted by a couple of kilos.

The other interesting thing to think about is Alphas. You've got a pretty tidy Alpha Sailquick. So if you go in at 16m/sec, about 32 knots, and want to exit on course for a 50 metre proximity, that's a radius of 25 metres. v squared on r = 10 m/sec squared = 1 g. So you're pulling 1 g in the corner. The fin, board and sail have to find 100 kg of lift towards the centre of the turn.

Normally the fin lift opposes sail lift but in a tight turn they both work together. I suppose that's stating the obvious, I only figured it out when I kept spinning out in the opposite direction. (I'm a bit heavy footed)

How much of the lift does the banked board contribute?

I always wonder about the explanation that you sheet in hard going into a gybe to "depower the sail" I'd think you sheet in to get all the power you can, it's going to pull to the centre of the turn just where you want it. The aerodynamic sail is probably much more efficient at generating lift than the board, so a good sheet in is what you need for least drag thru the turn.

This is a pretty rough estimate, you don't hold your initial speed thru the turn, you can tighten up the radius, and you might go wider than 50 metres and pinch up.

But a 1 g turn is what to aim for. Be a useful,feature of gps programs to calculate max g force during the alphas.

there is it's called gps action replay pro and it's had the feature for a couple of years now, not sure how accurate it is tho..

Ian K said......

But a 1 g turn is what to aim for. Be a useful,feature of gps programs to calculate max g force during the alphas.

Hey Ian, this is what you want, GPSar, enough info about your gybes here to make your head spin!

Most of it self explanatory, width is distance across the gybe path, durations in sec, in and out.
You pre set the run length on the distance slider at top of page.Distance is one leg ie 250 gives you a total 500 Alpha.
Uses the wind angle to find centre point of gybe (ie not lowest speed)
Does tacks as well as gybes...very interesting
Score........ is the ratio between max and min speed
T under...... is time below your speed pre set (top of page)
2-ktsT...... is the time it takes to reach 2 kts above 'speed under' pre set
Run length...... from the previous gybe

If you're not gybing like DBeck after all this, it could be paralysis by analysis

Ian K said...
>>>>>>>>

How much of the lift does the banked board contribute?

>>>>>>>>>>>>>

Back in my surfboard shaping days (late 60s early 70s), we were trying to minimise "spin out" in bottom turns. (I've had bottom turns at Margaret river that almost force me down on my knees)
No idea about Gs involved but it felt a lot.
We found that rail shape at the tail has a huge influence, as in all modern boards, sharp rails at the tail "bite" but the old rounded rails can pop out.

I've assumed it's the board/fin combination that holds the Gs.
My high G gybes are lay downs, don't think there's much sail pressure happening then.

But I guess any down pressure from the sail will help keep the board in the water.

Ian K said...

25 m/sec is fairly moving.

50 kts = 25.7222222 m / s = 92.6 km/h

Yep I would call that moving...

Ian K said...
>>>>>>

I find it pretty hard to carve a board all the way around in choppy water, but if you can time the sheet in right you get around a lot more neatly.
>>>

For me almost impossible, I'm used to slamming a wave board around on a wave out the back, and carving on flat water on the inside.
Gybing a speed board out in the middle of the estuary gives me untold problems.
Can't do a my normal lay down, because I bounce out on the chop, slowing the gybe down, I just stall.
If I can remember I'll give that a go.