Max Force Wind and Safety

[neilpride]

Originally Posted by jkleins

If that was how the scale was described I could agree it would be moderately useful. Unfortunately every scale I could find on the internet and the Annapolis Book of Seamanship starts with the wind speed range not the sea state. What the people in this discussion who use the scale are saying is ignore the wind speed and just use the force numbers to describe what you are seeing. That makes some sense. It does not make sense to me though in it's current written form as it tries to describe 2 things (wind speed and sea state) and bring them together when in real life they may not be related enough to do that.
One discussant mentioned that this is not for layman. Don't we all get a little ticked off reading a legal document that has to be "translated" for anyone other then a lawyer or talking to a doctor and not understanding a word they say. If you are using the Beaufort scale in a way that would "seem" non standard (ignoring wind speed measurements) and talking to a group of non-professional sailors it might have the same effect as the above mentioned cases.

Whereas the party of the second part hereby concludes that the party of the first part was not incorrect when making aforementioned statements and the party of the second part acknowledges their own inadequacy at deciphering the scale mentioned in the attachments, let it be known that the party of the second part regrets making certain statements that might have been construed to mean something to the party of the first part other then the intended meaning of the party of the second part and will hereby belay making statements similar to the above referenced statements now and in the future.

Or, I am sorry I said anything and will never do it again.

Jim

You are right Jim!!! a Force 7 is a Force 7 here and in Tokio, cold or hot, step seas or chopy seas , just a force 7!!! Best Regards.

[s/v Jedi]

Okay, I'll give it another go.

Let me start with this: I grew up on the water and Beaufort. We had no wind instruments other than a windex. The weather forecast put wind in km/h and the marine weather forecast used B.
When I wanted to know the wind, I looked at the water and could just tell what B scale it was, without thinking.

On to the windspeed in knots. I got a meter for that. I looked at it, took a table to find what B scale it was. Looking at the meter I had no clue or feeling about what it means for the conditions. Also, going up to one extra knot makes it another B scale? that's nonsense of course so the indications for wind speed are just that, indications.

Now, after so many years, I get a feeling for the conditions when looking at the wind speed indicator. I have learned it's language. But deep inside my brain I still thin in B scales because there's just too many knots over the full range to use it without grouping them.
You must look at it like a language, not a mathematical formula. You can translate but that is never perfect until you master both languages.

About temperature. There are good explanations but I'll try another approach. Look up to you sails and imagine that wind pushing you forward. It hits your sails with some speed. What you are actually looking at is a transfer of energy. Energy is more than speed, it is also the mass, just like that speeding bullet. A lighter bullet needs more speed to have the same impact as a heavier one. Cold air is heavier than hot air. So, when cold air hits your sails with the same speed as the hot air, the cold air actually transfers more energy into your sails. This is a big part of why most sailors state that sailing in cold conditions, like North Sea, Cape Horn etc. is tougher. They need to reef more than they are used to in the same wind conditions in warmer climates. But that's not where it ends: the cold wind also transfers more energy to the waves, so the waves are higher with cold wind than compared to hot wind. Your wind speed indicator will show the same reading, but you heel more and the waves are higher. The B scale includes the temperature automatically because it takes the sea state as the primary indicator.

So, it is NOT correct that a wind speed in knots translates to the same B scale in every part of the world. I think all sailors that took the courses learned how to apply the B scales and can use them easily. When you learned the trade from practice, looking at the wind speed indicator, you didn't learn the B language so you don't understand it. It's not difficult to learn though, there's only 12 words or so. Start looking at the white-caps, curling waves, breaking waves, white streaks of foam etc. and compare it to the photo's of sea state that come with the better B scale explanations. You see those white streaks, you know it's B6 which directly translates into a sail plan, what to reef how much. B5 doesn't have them, regardless of what the wind speed meter shows.

cheers,
Nick.

[Bash]

Originally Posted by s/v Jedi

Let me start with this: I grew up on the water and Beaufort. We had no wind instruments other than a windex. The weather forecast put wind in km/h and the marine weather forecast used B.
When I wanted to know the wind, I looked at the water and could just tell what B scale it was, without thinking.

Nick has described my experience to the T. I'd been sailing 25 years before I owned a boat with an anemometer. Frankly, I didn't need one because I could look at the water and objectively quantify conditions on the Beaufort scale.

Could it be, perhaps, that those who find the Beaufort Scale to be archaic tend to be those whose entree into sailing was on a boat with a full instrument package? I think my wife is this way even though she learned to sail on a Santana 22 without electronics. But that was long ago, and she never learned the B scale, and these days she looks at the wind readout to determine when and how much to reef. I look at the sea state. Guess which one of us calls the reefs more accurately.

The problem with anemometers is that they are the most unreliable instruments on modern vessels. Go back to the yacht club bar after a race and ask the navigators what true wind speeds they were seeing during the race. You'll be amazed at the disparity of answers. But we moderns want to trust our gauges more than our direct observations. Understandable? Yes. Obfuscation? Nope.

[barnakiel]

Yeah. Quite interesting to learn how different sailors tell how much wind there is. In my case it is the kind of sound the wind will make in the rigging. As a rule, I will say it is blowing e.g. 25, then look at the anemo to find it is only gusting 20.

b.

[jkleins]

Originally Posted by Bash

Understandable? Yes. Obfuscation? Nope.

it is only understandable if the person you are recounting it to using that terminology has the same understanding. If they don't then using it instead of plain English to describe the sea state/wind condition will "obscure" the understanding. It is not a matter of who is correct if communication is not occurring then it is not occurring.

I like what you guys are saying about the Beaufort scale and will probably brush up on it just for the heck of it after hearing how you use it but what you are describing is not what is written on most scales that are published and if someone were trying to learn to use it using those educational materials and not your years of experience then the points you guys are making wouldn't be coming across very well.

Maybe we should use a "Modified" Beaufort and leave out the wind speed.

Jim

[Wotname]

Originally Posted by jkleins

it is only understandable if the person you are recounting it to using that terminology has the same understanding. If they don't then using it instead of plain English to describe the sea state/wind condition will "obscure" the understanding. It is not a matter of who is correct if communication is not occurring then it is not occurring.

I like what you guys are saying about the Beaufort scale and will probably brush up on it just for the heck of it after hearing how you use it but what you are describing is not what is written on most scales that are published and if someone were trying to learn to use it using those educational materials and not your years of experience then the points you guys are making wouldn't be coming across very well.

Maybe we should use a "Modified" Beaufort and leave out the wind speed.

Jim

Jim,

You are a boat owner, sailor and skipper) - I assume. You are not a layman and I bet you use terms like port, starboard, bow, stern, abeam, halyard, sheet, spinnaker, springs, neap, tacking, heave to and so on. These are all jargon to my non-sailing friends yet they are everyday language to you and me. I am not a professional seaman and I am guessing neither are you but we use these terms 'cause they explain simply and easily we want to communicate .

So I am inviting you to come up to speed with the B scale so we can both talk simply and easily about wind force.

The B scale was never about wind speed, it was about wind force (as Jedi explained very well).

One great book is: Huler, Scott (2004). Defining the Wind: The Beaufort Scale, and How a 19th-Century Admiral Turned Science into Poetry.

or try this link Weather Doctor's Weather People and History: The Weather Legacy of Admiral Sir Francis Beaufort

In Oz, the weather people will make marine forecast something like say 23 to 28 kts, seas to 2 meters on a long 3.5 swell or some such. No doubt they are trying to accurate but a simple Force 7 would tell me what I needed to know.

And I can describe to you that we were sailing in force 4 yesterday morning and force 6 in the evening. You will know what my day was like and I don't need any wind instruments and don't have to guess at wave or swell heights.

[jkleins]

Originally Posted by Wotname

The B scale was never about wind speed, it was about wind force (as Jedi explained very well).

Then why is a range of wind speed the first thing listed in almost every depiction of the Beaufort scale I can find?

While we're at it why do we say port instead of left and aft instead of back? We do it to be a little bit nautical, to seem like we are in the crowd and part of the gang not because it is any better description. You can describe the left side of your car to your neighbor very easily but for some reason the left side of the boat needs a new term.

You went and got me started again.

Jim

[Ex-Calif]

While you cannot see the wind you can see the sea. A kilometer or so from our club the channel opens up to a large bowl area. As we get off the hook and look down towards the bowl I can see what the wind is like in the bowl always very different than the protected channel. We rarely get anything over 20 knots but by seeing the white caps out in the bowl I know its about 20 out there and will often shorten the genny to 100% in anticipation of the winds ahead.

I had a crew tell me one day - lets shake out the genny we are hardly heeling. 10 minutes later with the genny furled we had a rail in the water and were considering a reef in the main. Occasional white caps we furl the genny to 100%. Persistent and frequent white caps we put in a reef in the main and furl to about 80%.

I don't memorize beaufort and usually work in knots but the visual indications on the water are perfect for anticipating conditions ahead.

[bewitched]

Originally Posted by jkleins

Maybe we should use a "Modified" Beaufort and leave out the wind speed.

Jim

Not such a bad idea - the confusion only arose when someone decided to add windspeed to the scale. Before then it was very clear that it referred to sea state.

And you are also right about confusion being generated by the fact that most beaufort tables list windspeed first. In fact it gets even worse. In Hong Kong the Weather forecast will talk about F4 and 2m seas. The F4 being hyperlinked (on internet) to a scale which ONLY describes Beaufort in wind speeds. The inference being that Beaufort is a description of wind and the sea needs an additional descriptor - completely the wrong way round.

[barnakiel]

Originally Posted by bewitched

Not such a bad idea - the confusion only arose when someone decided to add wind speed to the scale. Before then it was very clear that it referred to sea state.

Well, yes - because when it was created, accurate wind instruments were not readily available (to the sailor). I bet, if they had today's technology back then, they would have based the scale on the wind speed, not on the sea state.

But times change and so do our understanding of the world and the instruments available to measure it.

To me, since it is very easy today to have an accurate wind instrument onboard and since we know that the amount of sail we can safely carry depends directly on the wind force, NOT ON THE SEA STATE, therefore it makes a lot of sense to refer the B scale to the wind speed.

Also, since the effects of the wind on the sea vary considerably with the depth of the sea, the current, the fetch and the time the wind has been blowing, I would always judge the situation and the action called for by the knots rather than by the B scale. But, as said above - it is so easy to have a wind instrument onboard today, ours does not even require electricity!

It is fine and desirable to know the B scale & its knots and m/s equivalents, just as it is fine to know how to use the sextant, how to tie the rolling hitch and decompress an engine without the decompression lever ...

Marine knowledge is complimentary by its nature and it is better not to acquire it on the 'either / or' basis. Learn everything, because everything is important at a time, if one has been sailing long enough ;-)

Know the B scale, sail by the wind instrument, understand the relationships.

b.

[Extemporaneous]

Originally Posted by barnakiel

just as it is fine to know how to use the sextant, how to tie the rolling hitch
and decompress an engine without the decompression lever ...

Can you explain how to do this or point to where I can otherwise read it?
Thanks.

Or PM me as to not cause more thread drift then I've already just done.

Regards,
Extemp.

[s/v Jedi]

Originally Posted by barnakiel

To me, since it is very easy today to have an accurate wind instrument onboard and since we know that the amount of sail we can safely carry depends directly on the wind force, NOT ON THE SEA STATE, therefore it makes a lot of sense to refer the B scale to the wind speed.

And THAT is where you and so many others go wrong and don't understand it. Your wind instrument does NOT show wind force. It shows wind speed. And there's a big difference between the two as shown in this thread, both for boats and airplanes. With all the modern instruments, airplanes still use the tables and wind temperature to determine the wind force, while us sailors can skip that because we can see the sea and waves and stuff. If you discard that as "old tech" you must start using the same tables used by pilots to find wind force from wind speed.

Also, the reason that the scales show the range in knots for every B number is that they are made for people who can only find the wind force in B by looking it up in a table using the knot reading on their instrument.

I think it's time to give up on this, laws of nature seem to make no difference at all for too many here ;-)

ciao!
Nick.

[jkleins]

Originally Posted by s/v Jedi

And THAT is where you and so many others go wrong and don't understand it.

Thank you for helping me make my point. The very fact that "so many others" don't understand it should suggest we need more then a force number to accurately convey our thoughts to "others" regardless of how clear it is to each of us individually.

Jim

[zydecotoad]

The density of air does not change that much from the temperature.

0 deg C, 1.29
30 deg C, 1.16

That's about 10% difference between really cold and really hot. The same difference would happen between 20 knots and 21 knots of wind. Or between 10 and 12 knots. Hardly a huge difference to a sailor.

Now on the Beaufort scale VS wind indicator to determine how much sail to raise ? I don't know about you guys, but I use the healing angle and helm feel to determine how much sail to carry. If I want to make a guess about how much sail I will want to use when I get out of the harbor, I will look and see how windy it looks. If two people look and one thinks, "hmm looks like Force 5, I better use the #3 jib", and the other thinks "hmm looks about 20 knots, I better use the #3 jib", then I don't understand the superiority of the Beaufort scale.

It also doesn't help that the Beaufort scale descriptions are vague and don't take into account the wind fetch and depth of water.

[bewitched]

Two ways to describe the weather at sea (not incl. temp, vis, precip etc). e.g.

1. Wind = NE, 11kts to 15kts, wave height = 3.6ft to 6ft, wave length = 12ft

or

2. NE 4

I really don't mind in which form the information comes - I understand that both are telling me the range of conditions to expect. I don't expect either to be on the ball completely and I don't set my sails to either, I set my sails to the conditions that I'm actually experiencing.

However, the forecast is not just for me, its for everyone out there, and sailors (with sails) are very much in the minority. Here in Hong Kong there is a large fishing fleet, as off China and Vietnam. The vast majority do not speak english, the vast majority would not have the first idea what Wind = NE, 11kts to 15kts, wave height = 3.6ft to 6ft, wave length = 12ft means

They all understand NE 4.

Dropping Beaufort and replacing it with detailed data will only misinform these people, the primary users of Navtex in this area.

I really can't see the advantage in adding more detail just because we can measure wind more precisely these days. It's still just a forecast and as such, will never precise anyway.