true vs. apparent wind

[Justin_NSA]

I've never had this luxury before. My instrumentation allows me to see true or apparent wind. I also have the classic 'Windex" at the mast top. Which indication of the wind is the preferred one to sail by? Or do you pros sail by the telltales?
I'm not even sure how 'true' could even be accurate unless you were sitting still. Is speed subtracted in order to compute true wind direction?

 

[Jackdaw]

You always sail (steer) by your tell-tails. Always always.

You wind instrument (set to apparent) is just an electronic windex.

Set to true it is used to make sail choices based on true wind speed, and true wind angle after the next mark.

Getting true wind from apparent indeed factors boat speed, and is a cosine function.

 

[alexco38]

True wind is nature, Apparent wind changes depending on your speed. The faster you go, the more forward you feel.

https://en.wikipedia.org/wiki/Apparent_wind

 

[Justin_NSA]

Thanks for confirming Jackdaw. I think for cruising, apparent wind indication may be sufficient. 'True' should tell us when to reef and/or furl a bit. The bottom line; they are all inputs used for better sailing.

 

[jssailem]

Real Sailors use the wind on their face and the breeze in their hair. When in doubt just spit. If you get hit in the face you are headed into the wind. Everything else will just support your sailor senses...

 

[Anonymous 121765]

Al & Jack hit it,

True wind is the true direction however, your boat sails by apparent wind.
Think of it as simply flying sideways. There is not much of a difference.
We all fly & sail by apparent wind.

Hull shape, sails shape/sizes & positioning factor in. So, just be a pilot & fly with what you got.
When hitting the, "Sweet spot," it's pretty apparent.

CR

 

[Scott T-Bird]

Why not try it both ways and see how you prefer it? Racing, you may prefer true wind. Aimless sailing (cruising) you may prefer apparent wind. If you have a system where you can set it both ways, that would also indicate that you can set your autopilot to sail by the apparent wind, as well. It (autopilot) should make course adjustments based on the input of apparent wind, which is also influenced by wind speed as well as direction. I'm not sure if this feature is similarly used with true wind as the input. Obviously, that's not a feature to use when racing, but it may be enjoyable when you have no particular place to go!

 

[Justin_NSA]

I'm thinking apparent wind indication when heading downwind would be an earlier warning of an accidental gybe. My wife can only focus on one input. if I can tell her to watch the gauge for apparent wind, she'll be much happier.
On the lake, I only use autohelm when I single hand, to get the sails up or down or maybe fetch a beer below.

 

[Cayennita]

I raced on a Farr 30 in the Caribbean and the season with the most wins including a Rolex was when the yard broke the carbon mast and instrument wires to the top. All we had was boat speed and depth. I stll sail and race with no instruments on my Catalina 30 and get podium in almost every regatta. You need to feel the boat, the wind the heel, the helm. I have a wiindex up top but I can't look up. All I use is tell tales on the shrouds and the sails.
Betsy Alison explained once the going up wind, you try to get the bow to do a nice sliw circle. Play the waves, look around at the sea, sails, tell tales, make adjustments, repeat.

 

[Rick486]

You always sail (steer) by your tell-tails. Always always.

You wind instrument (set to apparent) is just an electronic windex.

Set to true it is used to make sail choices based on true wind speed, and true wind angle after the next mark.

Getting true wind from apparent indeed factors boat speed, and is a cosine function.

Remember the accuracy of the "true wind" readout on your electronics depends on a calibrated speed through the water instrument networked \.

 

[capta]

If your wind instrument is connected to your gps it has a relatively accurate boat speed to calculate apparent wind with, but if it is connected to a speed log then the error in that can significantly affect the reading.

 

[Ward H]

Are they different at the top of the mast than at deck level?
I ask because the last time we were out we were out we discussing the virtues of buying a new jib. The admiral started to pay attention to the sail trim thingys (tell tales) and noticed the windex was showing us sailing close to the wind but the light ribbon on the windward shroud showed us on a beam reach. (that way and that way). I've seen it before but I steer towards a direction and trim to apparent wind at the index. Never though much about the deck level ribbons except to help explain things to visitors.

 

[Anonymous 121765]

It does not matter what the true wind is, as your boat will sail at an apparent-to angle.
This is again, based on shape, sail & location.

Wherever the TRUE wind comes from, your boat designed differences are adjusted.
Let's say you're closed-hauled. The true wind & your boat's performance angle will always differ somewhat.
Maybe 5°, maybe 10° off true. So you are not sailing true wind but Apparently, you're still using this.

CR

 

[Scott T-Bird]

Ward, I've only paid any attention to telltales on the sails. I've never cluttered my shrouds with ribbons. Somebody would have to tell me what you are supposed to see with them. I've never thought they would serve any purpose.

 

[Cayennita]

Wind farther aloft is both stronger and at a different angle than at the surface. That is due to friction. Your sails need to be properly "twisted" to match that shape. It can also be different on each tack. wind shear in one and none in the other. Shroud tell tales are very important. The more you use them, the more information you can gain. They will tell you wing angle. Down wind they can tell you if you are DDW or at an angle. The wind changes and you can adjust your helm. Many times going downwind I will go by the lee and create a reverse flow on the main on purpose. I can go lower on the course and also helps to keep the jib filled when wing a wing.

 

[Roland5048]

I agree with Scott. It drives me crazy when I get on a boat with shroud ribbons and no tell tales. The ribbons only tell you what is happening at seven or so feet above the deck. And not very well at that. Tell tales, when placed correctly, give a much more accurate picture of what the wind is doing along the whole length of the sail.

 

[Justin_NSA]

If your wind instrument is connected to your gps it has a relatively accurate boat speed to calculate apparent wind with, but if it is connected to a speed log then the error in that can significantly affect the reading.

True. My input comes from the knotmeter in the hull, not the GPS. It's affected by position, so likely not real accurate but close enough for me.

 

[Jackdaw]

Telltales in the shrouds are vitally important when you are sailing down-wind with Spinnaker, or sailing in very light, shifty airs. Telltales on the sails tell you how to drive. Telltales of the shrouds tell you where the wind is coming from. Hugely important distinction if you want to sail fast.

 

[Roland5048]

OK, I have to amend my previous post, #16, after reading Jackdaw's post. I can see the value in them when sailing downwind as the sail tell tales will be hanging down. My question: Do you put several of them at different heights on the shrouds as you would put on the sail?

 

[Kermit]

Ward, I've only paid any attention to telltales on the sails. I've never cluttered my shrouds with ribbons.

Scott,
Please don't tell my sister-in-law that. She'll want to go back and take them off my boat again!