While it's winter, I was thinking about combining a small digital anemometer / wind direction meter with a gps (speed, heading) bluetooth module and use a PDA with data logging software (like Labview) to combine these values. This way you may just be able to train with a single boat and possibly determine optimal settings for upwind sailing (upwind VMG, corrected for windspeed)

only problem, where can I find a small, but strong and cheap
anemometer? and where to mount this on a f18 (probably masthead?). Has anyone tried this before, or is my thinking too complicated and should I just go sailing... (don't forget, it's winter here <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" />)

Thanks!

I have been thinking along the same lines. My idea was to use feed from a local weather station instead of an anemometer, but your idea is better providing such a device can be sourced.

Gareth
www.fourhulls.com

The rotating mast makes mounting a wind direction sensor on the mast head very complex. You must correct the wind direction for the rotation of the mast. There are systems available for this but they are not cheap.

If you just go with wind speed you might be able to adapt a monohull system with a NEMA output. It's going to be big and heavy and need 12V power. There have been cheap wireless anometers announced in magazines but I have never actually seen one.

I saw a system just like you want, last year(minus the rotating mast correction). It was for a small monohull. They told me it cost their sponsor over $20,000. They used standard sensors interfacing to bluetooth modules. I really liked the wind speed/direction it was just a dome.

It is possible to build a system like this. If you do I would like the details.

For training a recording GPS that can calculate VMG for marks with known locations and more time on the water would probably be better.

The new S-10 Velocitek records 8 hours of GPS data that you can download and interface with Google Earth.

The rotating mast is a serious problem.
It would be easier to place the sensor somewhere else - is there any other suitable spot? On my H16 I had one below the bridle, but the snuffer makes that place a bit difficult.

About the velocitek - I have a foretrex 201, very nice, but with shifting winds not quite accurate enough for training purposes.

guess I'll have to think a little bit longer...

how about this?

http://www.airmartechnology.com/uploads/brochures/weatherstation.pdf

gary

Tacktick makes a device for rotating masts.
http://www.tacktick.com/products/product_view.asp?prod=82

One problem is weight at the mast-top. It seems that most sensor types are rather heavy.
What about placing the sensors under the snuffermouth? What is your experience with placing a wind-indicator/Windex/sensor there?

Stein

That would be perfect! but you would probably have to bring a big battery aboard..

You wouldn't need a mast-rotation correction if you'd correct your wind angle using GPS data. That would be just another (not so complicated) feedback loop in the datalogging application you'd have to write.

So then a masttop windsensor could still be usable...

Suunto do a good range of gadgets like that.
This watch does GPS with fast intervals and uses compass settings to log against marine charts ect and you can sync it up with the weather info and there marine watch alows for course layout.

They may do a wind meter system.
http://www.suunto.com/suunto/main/produc...D=1138799147005