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Go Back   SailNet Community > On Board > Gear & Maintenance
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  #21  
Old 11-28-2008
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Giulietta is just really nice Giulietta is just really nice Giulietta is just really nice Giulietta is just really nice Giulietta is just really nice
Negrini, I don't know if you actually understood or not...

What I meant, is here, we use true wind to measure the merda de boi that goes on in the BFS thread....get it?

over there, the true wind is allways up by 50%...
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  #22  
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Quote:
Originally Posted by Giulietta View Post
Jim,

the ST60 is NOT to be used to tell you where, as in which magnetic direction, the wind is coming from..it's used to tell you, in relatiion to your bow, where is the true/apparent wind and how strong they are...

It's a sail realted instrument, not a navigation instrument.
What the Portagee is attempting to differentiate here is the difference between true wind direction and relative wind direction. (Neither of which has anything to do with apparent wind.) Without a compass interfaced, all readings for true wind (and relative wind) will be referenced to the angle off the bow, the relative angle or the relative wind direction. The vessel's heading must then be applied to the relative wind angle to derive true wind direction. To do so automatically you'd need some type of heading input such as a flux-gate compass or GPS.

All of this gets back around to my frustration with "those people" who, one, seem bound and determined that every instrument on board will be from their company and, two, drop the ball repeatedly when it comes to interfacing logically interfaced components.
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  #23  
Old 11-29-2008
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Quote:
Originally Posted by Giulietta View Post
It is nothing more than a sailing aid...
Which would be my purpose. My main reason for wanting to know true wind speed is to know if I'm getting the most I can out of her for given conditions. Sure, we can go back to Sailflow, after the fact, but, especially sailing on Lake St. Stupid, as we do, what the buoys report and what was reality are not necessarily the same thing. An exchange between xort and I a couple months back, where we'd both been near, but on opposite sides of the same buoy, at the same time, and experienced completely different wind conditions was a perfect example. Secondly: True wind bearing would be handy, during races, for determining favoured tack: No?

Jim
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  #24  
Old 11-29-2008
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Guys :

What is the difference between relative wind and apparent wind?
Are they not the same?... I mean, wind relative to the boat being the same as wind apparent to the boat?


The difference between true and relative I can grasp, but between relative and apparent ? Surely they are the same?
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Quote:
Originally Posted by negrini View Post
Xort, No, it doesn't work !!
Did you look into that Seatalk bridge?

Quote:
Originally Posted by negrini View Post
If you have Raymarine, the only way to display the "almost true" wind is to install the ST speed.
I'd want that anyway.

Jim
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  #26  
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Jim,

the bridge works only if you have the SOW available in a different format (NMEA for instance), translating into/from Seatalk. If you like the ST60 Speed/Log, then you'll be ok, as it will put such sentence into Seatalk net. Should work plug-and-play.
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  #27  
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Quote:
Originally Posted by negrini View Post
Jim,

the bridge works only if you have the SOW available in a different format (NMEA for instance), translating into/from Seatalk.
Not true, according to the link Brak provided: gadgetPool.de Forums-viewtopic-SeaTalk-NNMEA-Bridge : True Wind direction SOG/STW (from the thread you referenced earlier in this thread). That device optionally rewrites SOG sentences to STW sentences, fooling the ST60 wind instrument into thinking it's getting what it wants.

It's unforutunate Raymarine's marketing and engineering departments are so moribund as to make a 3rd-party "hobbiest" device like this necessary for something so trivial. Raymarine is a division of Raytheon. The latter is a big supplier of high-tech military hardware to the the U.S. military. Things that make you go "Hmmm..."

That device isn't iimportant to me, being as, as I noted earlier, current is almost never much of an issue where we currently sail. For us: The ST60 speed log's output would do the trick, and we already have that device. (Not that we're inclined to spend over US$1000 on the wind instrument, anyway. I started this thread out of simple curiousity.)

Jim
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  #28  
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oooops ! you're right. I did same using my laptop for a while. But following term strictly, this is not a bridge, as shouldn't modify the content, just the envelope. Anyway, I didn't try this product but looks wise since they realised right a way the use of STW is wrong. If you have a chance and try it, let us know ....
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BTW, as per Beneteau "give away" I have a ST speed/log too. But this is a real mess to plug the paddle. I don't consider myself skilled disabled, but I find it somehow difficult to plug it. Is there any tip or different procedure people use to cope with that ?
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Quote:
Originally Posted by negrini View Post
BTW, as per Beneteau "give away" I have a ST speed/log too. But this is a real mess to plug the paddle. I don't consider myself skilled disabled, but I find it somehow difficult to plug it. Is there any tip or different procedure people use to cope with that ?
If you're talking about removing the transducer for cleaning and putting it back in: Yes. Tho no procedure is going to completely eliminate some water getting in, the man who surveyed our boat said the mistake that most people make is trying to remove one and plug in the other all in one go. Instead, he said, remove one, quickly slap your hand over the hole, grab the other and quickly plug it in.

I'm still working on being quick

Because our boat spent so much time in her slip this last season, the paddle-wheel on the transducer was reluctant to move freely. On the second cleaning I finally got it good and clean and we never had any further trouble. I'm going to stash a small rosin brush on-board for that purpose. A small, relatively stiff-bristled paintbrush would work, too.

Jim
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