Terminology ........ Whats your Flavour?

[Maine Sail]

Originally Posted by El Pinguino

I shall continue to consider 'merkin english an alien tongue.

El Pinguino.... never wrong but quite often mistaken....

I had no idea the new language was derived from a pubic wig. This, I find fascinating.......

[Tantalus]

Originally Posted by El Pinguino

Likewise.... who would have thunk that 'merkin english uses the term 'tidal current' but then these are the people that say 'left rudder' and 'right rudder' and have you ever heard them try and pronounce 'buoy'?

'Tidal current' is an expression you would never hear uttered by someone raised in the british nautical traditions and capable of speaking the Queen's english.

I shall continue to consider 'merkin english an alien tongue.

El Pinguino.... never wrong but quite often mistaken....

That's why no one over here seems to get the old joke about the sailor telling his optometrist he needs glasses because he just can't pick up bouys at night the way he used to,

[Coops]

Originally Posted by Maine Sail

I had no idea the new language was derived from a pubic wig. This, I find fascinating.......

George Bush Jnr, an apt name considering, was always saying that he was proud to be one.

Coops.

[cwyckham]

Originally Posted by El Pinguino

Likewise.... who would have thunk that 'merkin english uses the term 'tidal current' but then these are the people that say 'left rudder' and 'right rudder' and have you ever heard them try and pronounce 'buoy'?

'Tidal current' is an expression you would never hear uttered by someone raised in the british nautical traditions and capable of speaking the Queen's english.

I shall continue to consider 'merkin english an alien tongue.

El Pinguino.... never wrong but quite often mistaken....

I don't get it. There are two types of current. Some are caused by the overall flow of the ocean due to salinity, temperature etc. (such as the gulf stream) and some are due to tides flowing in and out around islands, etc. What the heck else do you call the second type?

Since one is fairly constant and the other changes with the tides, it is quite useful to distinguish them.

[El Pinguino]

Originally Posted by cwyckham

I don't get it. There are two types of current. Some are caused by the overall flow of the ocean due to salinity, temperature etc. (such as the gulf stream) and some are due to tides flowing in and out around islands, etc. What the heck else do you call the second type?

Since one is fairly constant and the other changes with the tides, it is quite useful to distinguish them.

'Tidal streams' is used in the real world to avoid confusion. Mind you calling the Gulf Stream the Gulf Stream is obtuse and just plain silly...

http://www.ukho.gov.uk/ProductsandSe...l_coverage.pdf

[StuM]

> these are the people that say 'left rudder' and 'right rudder'

As opposed to "left hand down a bit" and "right hand down a bit"?

(Reference to old BBC radio program for those too young/foreign to recognise it)

[Dockhead]

Originally Posted by goboatingnow

Ground wind is not " irrelevant " as far as sails go. It's the primarily motive power. Water referenced wind is used in polar to remove the effect of current generated winds , so as to produce a symmetrical polar not influenced by tide. But it's a mathematical abstraction , you can only experience true ( land wind ) md apparent wind. You can never experience water referenced wind

Dave

This is backwards, Dave.

The primary motive force is sheer between air and water, the relative motion between the two media. So True Wind is the most direct and mathematically simple way to describe this. Your keel is in the water and your sails are in the air -- water, air. Ground is no part of it, unless you are at anchor or moored up.

Of course, you can also describe it as Ground Wind plus "current wind" -- absolutely you can do it like you propose. But this one is the mathematical abstraction, not True Wind. You can also describe it as the speed and direction of the wind (in three dimensions!) in relation to the core of the earth, plus the vectors for rotation of the earth, and plus the vectors for "current wind". Also absolutely valid and mathematically sound approach, just one level more abstract than Ground Wind.

If you want to talk about "experience", then strictly speaking you cannot experience either Ground Wind or True Wind. You can only actually "experience" Apparent Wind. From the point of view of your experience, True Wind is closer to you -- it's just one step removed from Apparent Wind, and you actually will "experience" True Wind if you take way off, change heading -- it will be manifest in the changes in Apparent Wind, which is what you actually feel. Ground Wind is furthest from any experience, so this statement: "you can only experience true ( land wind ) " is simply incoherent.

[El Pinguino]

Originally Posted by Dockhead

This is backwards, Dave.....incoherent.

Its beyond backward and incoherent.

A practical example.... there is a massive high of 1028 sitting off the east coast of north america and you are sitting on your boat in the gulf stream which is running thereabouts at 4 knots ( nb... 45 years since I have been in the western north atlantic so maybe you don't get highs like this).

The 'ground' referenced wind is 0 knots so Dave is becalmed while I am gliding along under genneker in a 4 knot northerly.

Or refer back to my previous... same high pressure system... not a breath of wind ashore... you are in an estuary where the tide is running at 4 knots. Are you be becalmed? Nope.

[Hoofsmit]

Well since I started it, I have just read 11 pages and we still don't appear to have an accord on CF.
It has been enlightening and informative , thanks to everyone for your points of view but I think ' it's best to agree to disagree

[JPA Cate]

Oh, but Hoofsmit, you gave it a really good go, but before you go, can we all try to agree that "Break" is useful on VHF?

Go Boating Now, consider that you are the VHF operator in a boat standing by a dismasted vessel, and are coordinating a rescue between two other involved stations.
"Roger," [name of land station], "will relay to 'Rescue 1', "Break." "Rescue 1, blah blah"...."Roger, break with you, " back to land station with new information, and so on.

Interestingly, the Spanish use "cambio", and the French, "changez" both of which mean "change" in the place of "over". And it's perfectly understandable. Anyway, language use is always mutating. While one may decry some of the changes, they're still there.

Cheers,

Ann

[Hoofsmit]

Ann

As stated above not this side of the pond...... I think it is a matter of ' when in Rome'
Break is not a pro word and is unnecessary as the station name is alway used if you need to change who you are addressing.
If you are unsure if the change of station addressed needs clarification , ' over' is used to finish that conversation with a slight pause and the new station readdressed.
But that is here
if you do use break , I am sure no one will shout at you


Sent from my iPad using Cruisers Sailing Forum

[Alan Mighty]

Originally Posted by Tantalus

It just occurred to me that, while there have been several sources cited establishing true wind as being relative to ground or true north, there have been no citations of literature regarding the contrary view that true is based on "water wind". Any citations please?

The oldest use, in English, of "true wind" that I've been able to find is Alexander Dalrymple in 1769 using "true wind" to mean the gradient wind in contrast to the local wind (subject to land breeze, sea breeze or, as Dalrymple discussed, island effect wind).

The next oldest use is the famous Swiss mathematician Leonhard Euler in the 1790 English translation, by Henry Watson, of the work known in English as "A complete theory of the construction and properties of vessels". Euler showed how to compute "true wind" by vector subtraction of the direction and speed of the sail from the vector of the apparent wind. That amounts to "true wind relative to the water bearing the vessel". In other words, definitely not "ground wind".

If you hold your tongue centred while you click the link, you may see Watson's translation of Euler courtesy of Comrade Google: A complete theory of the construction and properties of vessels, p. 166.

[Scot McPherson]

In my ham days, BREAK was used to stop a current conversation because something more important or urgent needed to use the waves.

BREAK BREAK BREAK this is N2UPA BREAK BREAK BREAK...

Go ahead break...

[Dockhead]

Originally Posted by Alan Mighty

The oldest use, in English, of "true wind" that I've been able to find is Alexander Dalrymple in 1769 using "true wind" to mean the gradient wind in contrast to the local wind (subject to land breeze, sea breeze or, as Dalrymple discussed, island effect wind).

The next oldest use is the famous Swiss mathematician Leonhard Euler in the 1790 English translation, by Henry Watson, of the work known in English as "A complete theory of the construction and properties of vessels". Euler showed how to compute "true wind" by vector subtraction of the direction and speed of the sail from the vector of the apparent wind. That amounts to "true wind relative to the water bearing the vessel". In other words, definitely not "ground wind".

If you hold your tongue centred while you click the link, you may see Watson's translation of Euler courtesy of Comrade Google: A complete theory of the construction and properties of vessels, p. 166.

Very interesting. I think it's fairly natural that for a mathematician, it's going to be the relative motion of air and water which is interesting, as that is what we sail in. But I was surprised to see such an early reference; good work, Alan Mighty.

I think we should all agree that everyone can use terminology the way he wants. "True wind" can be ground-relative for those who prefer -- then it's the same as "true wind" for someone standing on land; for meteorologists for example. The fact that this will cause you all kinds of problems when trying to sail in moving bodies of water is your own problem, which can be solved be adding the idea of "current wind" as someone proposed above. That is pretty convoluted but it works.

Just remember, however, that your instruments have three different winds:

1. Apparent Wind
2. True Wind
3. Ground Wind

Number 2 is water-referenced, and Number 3 is ground-referenced.

Number 1 is the raw output from our wind instrument -- what you feel, relative to your bow.

Number 2 is Number 1 with Heading and Speed Through Water filtered out. Expressed in degrees from your bow. Useful for understanding what Apparent Wind will be when you change heading.

Number 3 is Number 2 with water motion filtered out (or Number 1 with COG and SOG filtered out). Usually expressed in compass direction, and useful for planning longer term, across tides. For understanding what the wind (both Apparent Wind and True Wind) will be when the tide changes.

I would suggest that using the terminology like what your instruments read is much easier and more logical, than using it like a land-based meteorologist who has no use for water-referenced wind. This is terminology appropriate for marine use, in my opinion.

I apologize if I am repeating myself -- the thread is rather old.