Thread: Beaufort Scale
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Old 3rd July 2011, 06:07 PM   #3
Join Date: Sep 2006
Posts: 459

I too was concerned with comments dismissing beaufort scale, but like normal I suspect its got lots to do with where you sail.
Having the experience to look out to sea and rig correct sail is a skill not to be undervalued. Using an anerometer is at best a guide and at worst totally misleading.There are many pitfalls relying on anerometer readings.. Wind at sea is rarely as found on beach ;probably near cliffs;hills or trees. Wind increases at top of cliffs when onshore and wind at height bares little resemblence to that at sea level.
I find wind speeds abroad (ie in warm climates) have to be at 3 or 4 mph higher than home for similar power.Cold air is denser; a modern ICE engine can not rely on a simple air flow metre, it needs air mass sensors (ie takes temperature and hence density into account) An anerometer can do no such thing.

The beaufort scale on the other hand is totally based on the wind`s effects on the sea which is much more useful than simple airspeed.Denser air will have more effect on seastate.Its the better guide.There is rarely a day with a constant wind;Beaufort has this covered.It gives a likely range of windspeeds having similar effects on sea state.Might be old be certainly far from outdated.IMO its gives much more meaning than simple windspeed; but its designed to be "subjective" and given from looking at sea state and not direct from an anerometer.Thats the whole point.Converting to Beaufort is pointless.

I can not accurately guess airspeed but I never try to. I look at sea conditions and decide on sail size from that. A flat sea;offshore wind;little chop results in a larger sail than less air speed;rough water big waves.

The beaufort is something we can all understand; it serves its purpose perfectly. I stopped trying to use anerometer years ago but its something we all have to go through. On lakes; flat water making a choice between 10 metre and 11 well fair enough but thats a decision I never have to make.
Assuming we all need or would benefit from an accurate knowledge of windspeeds and which sail to use is fundamently an error. Windspeed is only one aspect of many variables when choosing sail size. The prescriptive method mentioned on other thread would not work for me.

PS I use mixture of beaufort and knots ??? Never use metric or mph ??? Has led to confusion when abroad (Europe) where KMH is standard unit but on a scientific note the SI unit of speed is metres per second; which I would never dream of using.
Admiral Beaufort did a splendid job. If it aint broke dont mend it..

We all love F5 sailing; we all know exactly what that means whatever sail we choose for F5..

Last edited by Floyd; 4th July 2011 at 03:54 PM.
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