Will the wind speed be the same?

[Caer Urfa]

I am thinking of fitting a wind speed indicator, however I am not planning to drop the mast for at least another year unless I have too.
If I fit a wind speed indicator on the pushpit rail would I get the same reading then fitting it on-top of the 30' mast which I know is the usual place but bearing in mind my average speed under full sail is about 4.5 to 5.5 knots and I am not trying to get the wind speed reading to the nearest knot decimal place and it will be a lot easier to maintain and install!
Boat is a CW motor sailor.

 

[MoodySabre]

I would have thought that the reading (particularly a head wind) would be affected by the sails and the coach roof interrupting the air flow giving a false reading of strength and direction.

 

[Caer Urfa]

Take your point Moody!
I was thinking of also mounting it on top of a 300mm high pole which in turn is bolted to the 'top rail' of the pushpit rail, even slightly leaning over the stern!

 

[2Tizwoz]

No it won't be the same

unless you have an unsually high pushpit /forums/images/graemlins/smile.gif

 

[William_H]

If you are sailing on the wind in a decent breeze and yougo stand in the slot between the jib and mainsail you will be surprised at theincrese in wind speed through the slot. This is just one example of how the sails affect the wind speed.
perhaps the bow rail would be a better location as it tends to be the windspeed when beating that matters. (But then may be not)

Windspeed is probably a relative thing anyway such that if the wind speed reads higher or lower it won't matter so much to you. Wind direction will of course be all wrong. olewill

 

[sarabande]

Similar boat (?), tried it with a handheld anemometer, and the speed readings were all over the place. So the direction is likely to be ditto.

 

[wotayottie]

Providing its not half the real figure, does the accuracy of the wind speed figure matter that much in practise? And the direction even less since its only an issue when beating and then the sails will tell you how close you can go.

All I use my wind indicator for is to un-nerve myself when it gets past 25 and touches 30. If I hadnt got it I wouldnt know. Ignorance can be bliss.

So just like the log when you have gps, its redundant. Dont fit it - imho of course. /forums/images/graemlins/grin.gif

 

[widgeon]

I agree with several of the other responders that the readings will be very inaccurate if not from the mast head. If there is really no other choice, I notice that the magazine boat testers seem to put their temporary instruments on a pole strapped to the pulpit. Perhaps James Jermain can tell us how well that works.

 

[Drascomber]

Hi 2Tizwaz - where did this data come from? I want to know how to correct readings from my hand held anemometer.

 

[Bodach na mara]

From my own observations, windspeed at a level six feet above the water tend to be one Beaufort force less than the reading from the masthead forty feet above WL. That means that the difference in actual mph varies according to windspeed, but it is significant at all speeds. The whole issue is complicated near land however, and you often seem to get a gust earlier (or sometimes later) at the masthead than on deck!

 

[simonfraser]

the pbo testing team use a tacktick unit mounted on a short pole clipped to the pushpit !