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Has anyone tried moving the speedo to centerline

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Johan Hackman View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Johan Hackman Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2017 at 22:38
Roger,

Thanks for the link to the article. It proves that you are right but then again, the author of the article is wrong.

It's all about naming things. What is True Wind, really? As I stated clearly before, it is in relation to whatever object the air is moving that should determine the name of such wind. To me, and the instrument makers, the name "True wind" is referring to a mass of air moving across a mass of water. If you want a "Truer Than True Wind" you might find it truer to tell the wind across something that is not moving, as water sometimes does, such as the parts of the Earth that stick out of the oceans. Let's call it the "ground".

To call a mass of air moving an "apparent" wind is apt as it refers to whom it is apparent. To me, and so far the instrument makers, it is the wind that hits our faces when we are sailing. It consists of the air moving across the water together with the wind the journey across the water we sail generates, i.e. the speed wind that I referred to earlier.

Now, the author of the article calls the wind that you perceive on the water without the wind generated from the boat speed "apparent wind". It is "apparent", and very real (or "True", if you like) to someone who is disconnected from land but why not call it "perceived wind"? (Did I just invent the abbrevation PWS and PWA- Perceived Wind Speed and Perceived Wind Angle?) What I am saying is that if you call one wind one thing, you should find another name for another wind. The confusion should not about how to name different things.

I know I mentioned earlier that I have been discussing this earlier, and one of the places is Panbo.com. The editor of that blog (and whom I admire a lot) is Ben Ellison. After having very long discussion and a few almost heated arguments in the forum at his blog he wrote a blog post where he suggested True Wind should be renamed or redefined. I used the better part of this afternoon to find this blog post and I chuckled when I saw when the first commenter of the article you linked to was...

Johan
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Johan Hackman View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Johan Hackman Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2017 at 23:06
So if you follow the link you posted and check the link Ben provides,
http://www.panbo.com/archives/2013/03/the_equinox_celestial_mechanics_pesky_true_wind.html
, you will find my name in the article. I think this was the blog post I was looking for this afternoon.

Johan

Edited by Johan Hackman - 08 July 2017 at 10:36
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Johan Hackman Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2017 at 23:20
I find it amusing that if I look at the link you provide and follow the first commenter's suggestion to a link the first commenter is - me!

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Johan Hackman Quote  Post ReplyReply Direct Link To This Post Posted: 07 July 2017 at 23:39
I must say I am having a ball reading my own comments in that thread! I should go to bed but I pour myself a glass of red wine and have a good time.

I turns out I have already invented another type of wind - the "Hobby Wind"!!! This was already in 2013!!

Johan

Edited by Johan Hackman - 07 July 2017 at 23:44
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Post Options Post Options   Thanks (0) Thanks(0)   Quote High Time Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2017 at 09:44
Johan

It's becoming clear to me also that the problem is with names not principles or maths. True Wind, I think everyone agrees, is defined as wind speed and direction relative to the ground. 

The confusion has arisen amongst sailors because instrument makers have chosen to use the term True Wind to mean wind speed/direction relative to the water. Elsewhere it has been suggested that this should be termed Water Wind to avoid the confusion.

Instrument makers originally provided Water Wind info because it could be easily derived in the wind instrument if STW data was added.

With the advent of networked GPS SOG/COG data on most modern boats it is now possible to derive True Wind (relative the ground) and I suspect in a few years this will become generally available on mainstream wind instruments and plotters. As a social, rather than a racing, sailor, I believe True Wind is (marginally) more useful than Water Wind.

PS The link you provide to Panbo doesn't work for me. Does it still work for you?
Roger

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Johan Hackman Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2017 at 10:45
Roger,

I reposted the link so it works now.

Like I wrote above, I had a ball yesterday night re-reading all the discussions about True Wind I have been involved in. It's been a few years now and I kind of miss the late nights when I was trying to find ways get my points across. I also remember how difficult it was and I see that I in this thread start to walk in my own foot steps. Therefore I have decided to retire from the True Wind discussion.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote High Time Quote  Post ReplyReply Direct Link To This Post Posted: 08 July 2017 at 15:47
Hi Johan

Thanks for re-posting the link. I follow Panbo as I am particularly interested in electronics and navigation etc. but missed the referenced thread the first time around. It's interesting to see the discussion has been doing the rounds for several years now (and to note that Ben's position on True Wind is similar to mine  Thumbs Up).

I think we are actually in agreement that it is really only a terminology issue, so I, too, will bow out gracefully from this thread.

Fair winds.
Roger

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Post Options Post Options   Thanks (0) Thanks(0)   Quote StavrosNZ Quote  Post ReplyReply Direct Link To This Post Posted: 09 July 2017 at 21:47
All very fascinating and technically correct but again i have upgraded my instruments from Simrad to B&G Triton. For cruising (we have low tidal flows and falls) i use SOG, no paddle wheel to remove and clean, no variation on either tack and the impact on TWS is minimal based on my observations. For cruising its low maintenance trouble free solution. 
Stephen
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iemand View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote iemand Quote  Post ReplyReply Direct Link To This Post Posted: 10 July 2017 at 07:09
How is your system calculation TWS without Speed thru the water? It must be the same as AWS?!
Hanse 312 MJ 2004 - Hanse 370e MJ 2007
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Post Options Post Options   Thanks (0) Thanks(0)   Quote High Time Quote  Post ReplyReply Direct Link To This Post Posted: 10 July 2017 at 10:17
Originally posted by StavrosNZ StavrosNZ wrote:

For cruising (we have low tidal flows and falls) i use SOG, no paddle wheel to remove and clean, no variation on either tack and the impact on TWS is minimal based on my observations. For cruising its low maintenance trouble free solution. 

I would do the same but the speedo (paddle wheel) also includes the depth sensor which I can't do without! I think I would also lose TWS/TWD as this needs the STW input (IS20 and NSS8 system).

Does the Triton wind system give TWS with reference to SOG (maybe as an option)?
Roger

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