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post #21 of 28 Old 02-27-2019
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Re: ambient wind vs true wind

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Originally Posted by JoCoSailor View Post
When sailing, you are more interested in the effect the wind has on the boat rather than measurements from a purely meteorological point of view, so True Wind is the preferred choice over Ground Wind.
I'm very familiar with NauticEd material and have to warn you that his material is based off European standards and nomenclature.

You often find some differences between his nomenclature and what may be common in the US.

He is not wrong just New Zealand
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post #22 of 28 Old 02-27-2019
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Re: ambient wind vs true wind

Yeah, you are right. Apparent wind, Gust and Ambient Wind are totally different terms.
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post #23 of 28 Old 02-28-2019
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Re: ambient wind vs true wind

Knowing all this stuff about apparent, ambient and true wind is a waste of time while sailing, because if the boat is moving, what you are experiencing is apparent wind. I never find the wind to be true, even standing on the dock, because it is never really steady. Knowing how to read gusts while sailing and determining lift is another skill that comes with practice. One needs to be particularly interested in actual wind sailing downwind (accidental gybes have taken down many a mast).
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post #24 of 28 Old 02-28-2019
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Re: ambient wind vs true wind

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Originally Posted by geoirishbox View Post
Knowing all this stuff about apparent, ambient and true wind is a waste of time while sailing, because if the boat is moving, what you are experiencing is apparent wind. .
I assume that this is sarcasm. But seriously, if knowing the true wind direction is a waste of time, how do you know when to tack and lay a mark or channel without having a general sense of the true wind direction.

The ambient wind vs gust discussion derived from a discussion of NOAA weather station wind readings on a particular day. Understanding predictions and recorded wind conditions in standard terminology allows you to better understand how to set up your boat based on the predicted or experienced conditions.

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post #25 of 28 Old 03-02-2019
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Re: ambient wind vs true wind

I am sorry I was a little cavalier when I mentioned knowing "true wind" is a waste of time. But "general direction" is about the best one can do while underway. Usually, I think determined by "pinching" while going to windward. Each tack will likely differ.
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You guys must be very bored.....
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post #27 of 28 Old 03-02-2019
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Re: ambient wind vs true wind

True winds.. Winds are almost always given in true direction by the weather forecasters in all forecasts. This gets to be very important because most of us sail using magnetic heading vs true to sail a course. Since there are only 3 kinds of wind, on the bow, to much or too little, one can always assume while cruising the wind is forward of the beam. So depending on where you sail, a good sailor always take the magnetic variation into account before setting sail and cursing the weather gods. Down here in the Caribbean that can be as much as 18 degrees. Back in the US the average I believe is 8 degrees of north. Read the compass rose on your chart plus annual variation to get the magnetic deviation. Now since the apparent wind angle will move forward of the beam when sailing, adding the two variations will determine how much you need to beat into the wind, take a tacking duel (getting beat to death and partner not happy)or just forget about it all and turn on the motor. The later will get you there fast , anchor down quicker to watch all evenings entertainment of others getting into the anchorage or dock. Plus you will be further along with your favorite adult beverage of choice. Did I mention the Admiral will be happier!

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post #28 of 28 Old 03-02-2019
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Re: ambient wind vs true wind

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Originally Posted by Melrna View Post
True winds.. Winds are almost always given in true direction by the weather forecasters in all forecasts. This gets to be very important because most of us sail using magnetic heading vs true to sail a course. Since there are only 3 kinds of wind, on the bow, to much or too little, one can always assume while cruising the wind is forward of the beam. So depending on where you sail, a good sailor always take the magnetic variation into account before setting sail and cursing the weather gods. Down here in the Caribbean that can be as much as 18 degrees. Back in the US the average I believe is 8 degrees of north. Read the compass rose on your chart plus annual variation to get the magnetic deviation. Now since the apparent wind angle will move forward of the beam when sailing, adding the two variations will determine how much you need to beat into the wind, take a tacking duel (getting beat to death and partner not happy)or just forget about it all and turn on the motor. The later will get you there fast , anchor down quicker to watch all evenings entertainment of others getting into the anchorage or dock. Plus you will be further along with your favorite adult beverage of choice. Did I mention the Admiral will be happier!

Melissa
Currently Bequia, Grenadines, St Vincent
Figuring out your point of sail is not all that difficult. You can motor directly into the eye of the wind... apparent wind direction is close enough to true wind direction (let's forget about current set for the time being). Now take a look around... at your surroundings and your boat on the plotter and the heading line ... that should pretty close to the direction of the true wind. If you destination or mark is forward of the beam and more than the lower (more) angle you can sail.... say 40 then you you can fetch the mark without tacking. Heck if you have a sailboat you can figure this out. NOAA weather is good enough to get you gears working and figuring out what you will be facing one you get off the mooring/anchor.

pay attention... someone's life depends on it
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