Hi all wind beggars,
Question 1:
Can anyone tell me, is there roughly relationship between the windsurfing speed we get based on wind speed?
Like use wind speed times 1.5
10 knots ?1.5= 15 knots
Sail is 5 m, times 1
10 m , times 2
15?2= 30 knots
So max speed can get 30 knots.
Other example, like horsepower, sails as bigger, power increase. 10m sail should be two times of 5m sails, so if same skill, same weight of surfer and board, same wind, 10 m sailer should be double speed of 5 m surfer.
I try to figure out efficiency of my skill. Like today, wind was 10 knot, how much speed I should get?
Today I could feel the tension, like full horsepower driving. Really want to know the speed I got. But I didn't need to use straps.
Till now, any windsurfing speed are two times of wind speed?
Question 2:
When do you start to use straps? reach some speed? or ? I don't think you use straps on 10 knots condition, do you?
Question 3:
Do I need some track device to record my speed? I am thinking about it.
If I need one, afterwards to check track and speed, don't check on the water,how much for a cheap one? water proof need. I read many related article at GPS part, so many vocabulary I don't understand. Alpha, 50....etc.
Thanks in advance.

Generally no. Far too many variables, not the least of which is that the sail takes the shape of a lifting body when loaded.

So wind strength isn't the only factor in max speed. Power available, is a direct relationship to your weight/sail size and skill. For max speed you need a sail that you can just fully sheet in. If it's any bigger you ave to sheet out, you get the same power but with more drag.
The other factor in max speed is drag, this is where skill come in, you have to trim the board and rig for minimum wetted surface area.

This where the straps come in You can be more fully powered up with feet in straps, and you have more control of board trim. I get in the straps as soon as I have enough speed to get my feet that far back, which is usually not long after I start planning.

It sounds like you are really interested, my advice is to join a GPST team
www.gpsteamchallenge.com.au
There are a few Qld teams.
Members will be very helpful, but to post there you need an authorised device. You may be able to get a second hand one, because there's only 2 new on the market at the moment. The GW60 has reliability issues and's about au$360. By far the best is the motion, but that's in short supply.

The relationship between wind strength and max speed isn't linear!
As long as you have the ideal sail size, available power remains constant, purely dependant on your weight and skill.
In lighter winds, the gear has to be bigger, so there's more dead weight and more drag, so there's a loss of efficiency. At higher winds, the rider starts to be a significant proportion of drag, so again a loss of efficiency.
As a very rough guide, (I'm only guessing here, and based on my experience of a light weight sailor around 65Kg). Fully powered at 10knots should get around 20kts, (I've never been fully powered at 10kts, I don't have a big enough sail).
20Kts of wind should get you doing 30kts, (for me anyway)
30kts, could get you to 40kts, (haven't made that yet)
And to do 50kts, I think you need a windspeed around the same.

so the ratio goes from 2:1 to 1:1

And that's on the ideal downwind angle, if you're sailing square the numbers are much less

segler said..
Generally no. Far too many variables, not the least of which is that the sail takes the shape of a lifting body when loaded.

Thanks.

As Decrepit said, the relationship between max speed and wind speed is not linear. Water state, sailor talent, height & weight, board, sail and fin size also effect max speed. For me at around 90kg and 173cm, sailing in flat water, I've recorded the following:
- wind speed: 13kts, Max 2sec speed: 28.8kts, sail: 8.5, board: 137 lt & 82 wide, fin: 46 pointer
- wind speed: 15kts, Max 2 sec speed: 34kts. sail 7.9, board: 137lt & 82 wide, fin: 35 deep weed speed
- wind speed: 20 kts, Max 2 sec speed: 38.6kts, sail: 7.0, board: 115lt & 72 wide, fin: 24 deep delta
- wind speed: 25 to 30 kts, Max 2 sec speed: 38.5kts, sail: 6.2, board: 97lt & 62 wide, fin: 32 pointer
- wind speed: 25 to 30kts, Max 2 sec speed: 39.4kts, sail: 5.7, board: 70lt & 50 wide, fin: 23 deep weed speed
- wind speed: 30 kts, Max 2 sec speed:40.3kts, sail: 5.4, board: 95lt & 55 wide, fin: 25 deep weed speed
At wind speeds under 15kts, the ration of max 2 sec speed to wind speed is over 2.
At wind speed greater than 30kts is approaches 1.

decrepit said..
So wind strength isn't the only factor in max speed. Power available, is a direct relationship to your weight/sail size and skill. For max speed you need a sail that you can just fully sheet in. If it's any bigger you ave to sheet out, you get the same power but with more drag.
The other factor in max speed is drag, this is where skill come in, you have to trim the board and rig for minimum wetted surface area.

This where the straps come in You can be more fully powered up with feet in straps, and you have more control of board trim. I get in the straps as soon as I have enough speed to get my feet that far back, which is usually not long after I start planning.

It sounds like you are really interested, my advice is to join a GPST team
www.gpsteamchallenge.com.au
There are a few Qld teams.
Members will be very helpful, but to post there you need an authorised device. You may be able to get a second hand one, because there's only 2 new on the market at the moment. The GW60 has reliability issues and's about au$360. By far the best is the motion, but that's in short supply.

Hi decrepit,
Thank you for your information.
The GPS team challenge website looks lots of data. Great to see many of Grand master aged fellows.
Can you private message me roughly the motion mini's price please?
What I want is, monitor myself, see where or which side need to improve. Give myself short term training direction.
Tracking looks useful. So that I won't lost my training direction. For example, need to practice turning/gybing, or get bigger sized sail, or decrease my board etc.

decrepit said..
The relationship between wind strength and max speed isn't linear!
As long as you have the ideal sail size, available power remains constant, purely dependant on your weight and skill.
In lighter winds, the gear has to be bigger, so there's more dead weight and more drag, so there's a loss of efficiency. At higher winds, the rider starts to be a significant proportion of drag, so again a loss of efficiency.
As a very rough guide, (I'm only guessing here, and based on my experience of a light weight sailor around 65Kg). Fully powered at 10knots should get around 20kts, (I've never been fully powered at 10kts, I don't have a big enough sail).
20Kts of wind should get you doing 30kts, (for me anyway)
30kts, could get you to 40kts, (haven't made that yet)
And to do 50kts, I think you need a windspeed around the same.

so the ratio goes from 2:1 to 1:1

And that's on the ideal downwind angle, if you're sailing square the numbers are much less

Yes, your conclusion like wind speed + 10 knots roughly.
I will need figure out my skill, based on wind speed to get how much to monitor myself.
Can I ask general how fast speed do you start to use straps please? thanks.

I remember going fast , it was soo long ago . When will we get wind again ?

John340 said..
As Decrepit said, the relationship between max speed and wind speed is not linear. Water state, sailor talent, height & weight, board, sail and fin size also effect max speed. For me at around 90kg and 173cm, sailing in flat water, I've recorded the following:
- wind speed: 13kts, Max 2sec speed: 28.8kts, sail: 8.5, board: 137 lt & 82 wide, fin: 46 pointer
- wind speed: 15kts, Max 2 sec speed: 34kts. sail 7.9, board: 137lt & 82 wide, fin: 35 deep weed speed
- wind speed: 20 kts, Max 2 sec speed: 38.6kts, sail: 7.0, board: 115lt & 72 wide, fin: 24 deep delta
- wind speed: 25 to 30 kts, Max 2 sec speed: 38.5kts, sail: 6.2, board: 97lt & 62 wide, fin: 32 pointer
- wind speed: 25 to 30kts, Max 2 sec speed: 39.4kts, sail: 5.7, board: 70lt & 50 wide, fin: 23 deep weed speed
- wind speed: 30 kts, Max 2 sec speed:40.3kts, sail: 5.4, board: 95lt & 55 wide, fin: 25 deep weed speed
At wind speeds under 15kts, the ration of max 2 sec speed to wind speed is over 2.
At wind speed greater than 30kts is approaches 1.

Very useful data.
Nearly 20 knots on top of the wind speed, why when wind speed increased, your speed dropped?
Why don't you use big sail when wind speed above 20 knots?

Imax1 said..
I remember going fast , it was soo long ago . When will we get wind again ?

How about this Thur and Fri? looks inviting!

Motsbane said..

John340 said..
As Decrepit said, the relationship between max speed and wind speed is not linear. Water state, sailor talent, height & weight, board, sail and fin size also effect max speed. For me at around 90kg and 173cm, sailing in flat water, I've recorded the following:
- wind speed: 13kts, Max 2sec speed: 28.8kts, sail: 8.5, board: 137 lt & 82 wide, fin: 46 pointer
- wind speed: 15kts, Max 2 sec speed: 34kts. sail 7.9, board: 137lt & 82 wide, fin: 35 deep weed speed
- wind speed: 20 kts, Max 2 sec speed: 38.6kts, sail: 7.0, board: 115lt & 72 wide, fin: 24 deep delta
- wind speed: 25 to 30 kts, Max 2 sec speed: 38.5kts, sail: 6.2, board: 97lt & 62 wide, fin: 32 pointer
- wind speed: 25 to 30kts, Max 2 sec speed: 39.4kts, sail: 5.7, board: 70lt & 50 wide, fin: 23 deep weed speed
- wind speed: 30 kts, Max 2 sec speed:40.3kts, sail: 5.4, board: 95lt & 55 wide, fin: 25 deep weed speed
At wind speeds under 15kts, the ration of max 2 sec speed to wind speed is over 2.
At wind speed greater than 30kts is approaches 1.

Very useful data.
Nearly 20 knots on top of the wind speed, why when wind speed increased, your speed dropped?
Why don't you use big sail when wind speed above 20 knots?

As I said, speed is influenced by many factors. The speed on the 7 was achieved at Lake George in perfect conditions. The 6.2 was used at Wellington Pt where the speed run is more technical.

The size of sail you can effectively use in a given wind depends on your leverage which is affected by your weight, height and technique.

Motsbane said..>>>>>>
Can you private message me roughly the motion mini's price please?
What I want is, monitor myself, see where or which side need to improve. Give myself short term training direction.
Tracking looks useful. So that I won't lost my training direction. For example, need to practice turning/gybing, or get bigger sized sail, or decrease my board etc.

It's extremely rough, numbers slip through this old brain like water down a drain. So I have $350 floating around in there somewhere. But as I said there's a very long delay. The mini motion, without a display is a lot cheaper, that allows you to post, but you still need on the water feedback. The cheapest way, is an old phone. I have a $40 phone from the postoffice, loaded with GPSLogit. The beauty of this it has an audio output, so you can listen to your speed as you sail. But it's no longer on the playstore, although there are a few version floating around here. There's another sailing app that's more directed at racing, I've never used it on the water, but I think it will give you enough info.
There are other smart watches on the market, that can be loaded with custom software, that people use along with the min motion.

decrepit said..

Motsbane said..>>>>>>
Can you private message me roughly the motion mini's price please?
What I want is, monitor myself, see where or which side need to improve. Give myself short term training direction.
Tracking looks useful. So that I won't lost my training direction. For example, need to practice turning/gybing, or get bigger sized sail, or decrease my board etc.

It's extremely rough, numbers slip through this old brain like water down a drain. So I have $350 floating around in there somewhere. But as I said there's a very long delay. The mini motion, without a display is a lot cheaper, that allows you to post, but you still need on the water feedback. The cheapest way, is an old phone. I have a $40 phone from the postoffice, loaded with GPSLogit. The beauty of this it has an audio output, so you can listen to your speed as you sail. But it's no longer on the playstore, although there are a few version floating around here. There's another sailing app that's more directed at racing, I've never used it on the water, but I think it will give you enough info.
There are other smart watches on the market, that can be loaded with custom software, that people use along with the min motion.

I will try my phone in a waterproof bag.
Thanks for advice and information.

Motsbane said..>>>
I will try my phone in a waterproof bag.
Thanks for advice and information.

Here's the alternative to GPSlogit, if you can't find a copy.
www.windsporttracker.com

Not sure if that's still in playstore as data is down here.

sboardcrazy said..
I bought a Garmin Forerunner 245 sports watch when they were on special ( about $270? ). You'd have to wait for it to be on special although there are probably others out there that get discounted.
It's not approved so you can't post into the GPSTC comp with it but feedback is terrific especially loaded with windsurfing datafields. It also does heart rate etc so it can confirm that you are buggered because you almost had a heart attack..
You can post your tracks on google Earth.
I find the on water feedback very motivating
Once you get a GPS device expect to be disappointed in your speeds.. It's easy to think you're doing 30kts and 100kms of distance when really you're only doing 23kts and 20kms.. less if you're learning.

30kts and 100kms of distance when really you're only doing 23kts and 20kms..

Lol.