Point of Sail

[charliegrau]

Maybe you should start your own thread. All of this apparent/true wind discussion we've been having is off topic and could be considered a "disservice". Personal attacks are also a disservice. So let's get back on topic....or go to another thread. I started this thread to try and get an answer to a simple question. Are "points of sail" expressed relative to apparent wind or true wind. Some say True. I always thought "Apparent". I thought apparent because the diagrams always show the wind in relation to the boat's bow. Others say because the word "apparent" was not used, it necessarily a reference to true. Does anyone have a definitive reference rather than an opinion? Please, if you just have an opinion or an argument or an off topic comment...start your own thread.

 

[charliegrau]

charlie, I think you're confusing the issue by dealing with coming out of a tack. Stay with Jack for awhile, he's right. ONLY consider what happens when you're already OUT of a tack and just ailing along. A puff hits. You have two choices:

1. Head up and LEAVE your sails just as they are

2. Maintain course and adjust your sails

Does this make it simpler?

I agreed with Jack regarding the effects of an increase in true wind. Now, if we ONLY consider the effects of an increase in boat speed (whether from coming out of a tack, getting better trim on the sails, hoisting additional or larger sails, etc) what happens?

 

[Bill Roosa]

Stu, I would interject that there is a third option, and much more to the point of sailing when not in a race,
you can do nothing and continue to chase the First mate around below deck. or have a refreshing drink. or take in the view, or .......

sailing is about relaxing. If I paid that close of attention to the sails my First mate would probably throw a life ring at me.

And the wind does come forward on all points of sail when the boat speeds up.

 

[Bill Roosa]

Ok I read the OP's post.
Points of sail are a way to talk about the wind. Which wind you ask? I would say that for most sailboats the difference between the true wind POS and the apparent wind POS is ignorable as there are only 6 POS (on each side). You would have to have one of those VERY high performance boats for your boat speed to have a different POS on apparent and true wind.
In the Army we called this "pole vaulting over mouse turds"

 

[Stu Jackson]

Hey, Bill, didn't you hear charlie?

Start your own darned thread! :bang:

 

[Stu Jackson]

I agreed with Jack regarding the effects of an increase in true wind. Now, if we ONLY consider the effects of an increase in boat speed (whether from coming out of a tack, getting better trim on the sails, hoisting additional or larger sails, etc) what happens?

Jut kiddin' before, charlie...

I really think you are confusing the issue by stating things like "...whether from coming out of a tack, getting better trim on the sails, hoisting additional or larger sails, etc..."

What happens is the boat speeds up and the AW moves EDIT forward (thanks to Joe to catch that original mistake on my part).

I think we can all agree on that, right?

The REAL issue as I see it is what I wrote in my last non-kidding post/question.

Once you are moving at any reasonably continuous speed, the ONLY thing that's going to change your speed (and NOT using your confusing issues) is a CHANGE IN TRUE WIND speed or direction.

If it's from the same direction, then you do either of the two things I mentioned. One will change your course, the other will change your sail set but maintain your course.

If one is racing, then the choice has to be made: do we want the lift to get to the next mark or do we want to maintain course? The answer will depend on what board you're on, where you are in the course, your "neighboring" racers, any land to the side of the course or course restrictions, and, when you get closer to the mark, your layline.

If I'm cruising, I take the lift and leave the sails set.

What happens if you change your sails or turn your motor on MEANS that you've increased the apparent wind, 'cuz reality is that you can't increase the TRUE wind by turning your motor on.

Does that answer the question?

 

[Bill Roosa]

Ha, Ha Ha
I may be just arriving at last week but I do know POS is not a math term and is just a way to talk about things

 

[Bill Roosa]

OK, is somebody actually suggesting the changes in wind speed and/or direction will NOT have some effect on your boat speed.
your comment Stu seems to be blindingly obvious to even those of us just arriving at last week.

 

[Joe]

I've been following this thread and, wow, it has legs. So, to summarize the relevant point here, I would say that you will have difficulty in distinguishing a velocity lift from a wind shift lift if you rely on the apparent wind. Either looks the same to the tell tails. The velocity shift calls for the ease, head up, trim response for optimum performance. The real wind shift lift doesn't. Since the wind velocity remained constant you merely follow your tell tails to a course more directly towards destination (Mark.) So you trim sails for the apparent wind but your response to a lift, or a knock, depends on the true wind. Is that a fair statement?

By god... that is exactly right. That's why you have a compass on your boat.

 

[Joe]

/

 

[Bill Roosa]

A couple of things
true wind does not necessarily come from the direction you want to go. So it is what we call in the community an independent variable. It can have any value at all.
so saying that the apparent wind does.......anything you want to say...... without specifying the true wind direction is kinda dumb.
another way of saying this is:
you can always find a combination of true wind speed and direction that will make the apparent wind "come foreword" or "go aft" for any boat direction and speed.

 

[Joe]

Bill's comment is very easy to understand... thanks..

My comment to Charli is that your original scenario is based on the assumption that the boat stops sailing and you must change course... to get it going again.

In reality, that is not the case. What happens is..... the boat starts slowing down... which moves the Apparent Wind Direction aft... to a point that the sails start lifting again. You don't have to bear off 15 degrees to get moving. You're already moving... you just slow down. The apparent wind angle will limit your speed on this point of sail. So what some sailors do is just keep bearing off watching the AW indicator, because they don't want to slow down, and they end up off course.

 

[Kings Gambit]

Here You Go, Charlie!!

Does anyone have a definitive reference rather than an opinion? Please, if you just have an opinion or an argument or an off topic comment...start your own thread.

For lack of anything better, here’s a definition from Henry Black’s A Law Dictionary.

Regarding Close-hauled
“In admiralty law this nautical term means the arrangement or trim of a vessel's sails when she endeavors to make a progress in the nearest direction possible towards that point of the compass from which the wind blows. But a vessel may be considered as close-hauled, although she is not quite so near to the wind as she could possibly lie.“

Clearly, the phrase “towards that point of the compass from which the wind blows” must be interpreted as the true wind direction. It is also clear that the definition refers to the arrangement or trim of a vessel's sails but says nothing about the actual heading of the boat relative to the wind except to note that “a vessel may be considered as close-hauled, although she is not quite so near the wind as she could possibly lie.”

The term close-hauled historically refers to the set and trim of the sails on a vessel that is essentially beating to weather. Our other “Points of Sail” reference a boat’s heading relative to “the wind.” The (yours above) POS DIAGRAM depicts the trim of the sails at those Points of Sail, but I think we have laboriously established that a boat sailing with the true wind on its beam will NOT have its sails trimmed as shown in THE DIAGRAM. The correct sail trim on the apparent wind that the boat would be experiencing requires closer sheeting than depicted.

How do we resolve this? “Close-hauled” is not a Point of Sail! It is a trim setting by its traditional definition. The three basic points of sail are therefore: Beating, Reaching, and Running. This resolves the paradox of potentially experiencing two points of sail on one true wind direction. A boat close-hauled and beating to weather that receives a “velocity lift" from a [constant] true wind direction is still beating and is still close-hauled by definition even if the boat does not come up, i.e., “But a vessel may be considered as close-hauled, although she is not quite so near to the wind as she could possibly lie.”

So, if you are reaching with the true wind abeam are you on the Point of Sail known as a Beam Reach? I suppose you are—even with your sails trimmed to the apparent wind arriving forward of the beam; but that trim HAS NO BEARING on the definition of the Point of Sail. Even if going so fast that the sails are trimmed in all the way you’re still on a beam reach BECAUSE when the boat is sailing [reaching] with the true wind on her beam SHE IS NOT ENDEAVORING TO MAKE A PROGRESS IN THE NEAREST DIRECTION POSSIBLE TOWARDS THAT POINT OF THE COMPASS FROM WHICH THE WIND BLOWS! Therefore, she cannot be close-hauled [read: beating] while on a beam reach!!

I stand corrected!! See slightly more correct POS diagram below; TWA means True Wind Angle.

Yours,
KG

 

[charliegrau]

For lack of anything better, here’s a definition from Henry Black’s A Law Dictionary.

Regarding Close-hauled
“In admiralty law this nautical term means the arrangement or trim of a vessel's sails when she endeavors to make a progress in the nearest direction possible towards that point of the compass from which the wind blows. But a vessel may be considered as close-hauled, although she is not quite so near to the wind as she could possibly lie.“

Clearly, the phrase “towards that point of the compass from which the wind blows” must be interpreted as the true wind direction. It is also clear that the definition refers to the arrangement or trim of a vessel's sails but says nothing about the actual heading of the boat relative to the wind except to note that “a vessel may be considered as close-hauled, although she is not quite so near the wind as she could possibly lie.”

The term close-hauled historically refers to the set and trim of the sails on a vessel that is essentially beating to weather. Our other “Points of Sail” reference a boat’s heading relative to “the wind.” The POS DIAGRAM depicts the trim of the sails at those Points of Sail, but I think we have laboriously established that a boat sailing with the true wind on its beam will NOT have its sails trimmed as shown in THE DIAGRAM. The correct sail trim on the apparent wind that the boat would be experiencing requires closer sheeting than depicted.

How do we resolve this? “Close-hauled” is not a Point of Sail! It is a trim setting by its traditional definition. The three basic points of sail are therefore: Beating, Reaching, and Running. This resolves the paradox of potentially experiencing two points of sail on one true wind direction. A boat close-hauled and beating to weather that receives a “velocity lift" from a [constant] true wind direction is still beating and is still close-hauled by definition even if the boat does not come up, i.e., “But a vessel may be considered as close-hauled, although she is not quite so near to the wind as she could possibly lie.”

So, if you are reaching with the true wind abeam are you on the Point of Sail known as a Beam Reach? I suppose you are—even with your sails trimmed to the apparent wind arriving forward of the beam; but that trim HAS NO BEARING on the definition of the Point of Sail. Even if going so fast that the sails are trimmed all the way in you’re still on a beam reach BECAUSE when the boat is sailing [reaching] with the true wind on her beam SHE IS NOT ENDEAVORING TO MAKE A PROGRESS IN THE NEAREST DIRECTION POSSIBLE TOWARDS THAT POINT OF THE COMPASS FROM WHICH THE WIND BLOWS! Therefore, she cannot be close-hauled [read: beating] while on a beam reach!!

I stand corrected!! See slightly more correct POS diagram below; TWA means True Wind Angle.

Yours,
KG

KG, thanks. I have to agree now that Points of Sail are in reference to the true wind angle and are meant to represent course in relation to true wind, rather than heading in relation to apparent wind. I think with the new generation of planing and foiling boats we may need different diagrams for different boat types when we start introducing sail trim terminology in our discussion of points of sail. According to this definition a boat sailing on a broad reach at greater than true wind speed could have a sail trim that looks more like it is on a close reach or close hauled as it works downwind.

 

[charliegrau]

Jut kiddin' before, charlie...

I really think you are confusing the issue by stating things like "...whether from coming out of a tack, getting better trim on the sails, hoisting additional or larger sails, etc..."

What happens is the boat speeds up and the AW moves aft.

I think we can all agree on that, right?

The REAL issue as I see it is what I wrote in my last non-kidding post/question.

Once you are moving at any reasonably continuous speed, the ONLY thing that's going to change your speed (and NOT using your confusing issues) is a CHANGE IN TRUE WIND speed or direction.

If it's from the same direction, then you do either of the two things I mentioned. One will change your course, the other will change your sail set but maintain your course.

If one is racing, then the choice has to be made: do we want the lift to get to the next mark or do we want to maintain course? The answer will depend on what board you're on, where you are in the course, your "neighboring" racers, any land to the side of the course or course restrictions, and, when you get closer to the mark, your layline.

If I'm cruising, I take the lift and leave the sails set.

What happens if you change your sails or turn your motor on MEANS that you've increased the apparent wind, 'cuz reality is that you can't increase the TRUE wind by turning your motor on.

Does that answer the question?

Stu, thanks...your first post was funny....we could use a little comic relief. I think your last sentence reflects what I said initially...so it seems we are on the same page. I'm sorry I confused anyone with my attempts to explain my point.

 

[Jackdaw]

I stand corrected!! See slightly more correct POS diagram below; TWA means True Wind Angle.

Yours,
KG

KG,

Its a good diagram.

One improvement would be to take off the descriptions of the sail shape. The actual sail shape (and sail selection!) is function of true wind speed and the particular boat in question.

 

[Kings Gambit]

Thanks. Yeah, that's why I said it was only slightly more correct than the others we've discussed. There's not all that much difference between illustrations of sail trim/position/shape and descriptions, if both media are basically either wrong, inaccurate, and/or misleading.

 

[Daveinet]

I can settle this once and for all.

A broad reach is when I forget to pass DW the Ketchup and she has to get it herself.

OK, before getting to the end of this thread, it always seemed logical that close hauled referred to the sail, not the boat. If you are hauling your boat, then it is on a trailer. Beam reach would mean the boat beam. I think the real problem lies in the fact that even though points of sail refer to boat position relative to true wind, no one really knows for sure what true wind is, unless they have instruments that are calculating it on the fly. Its only one's best guess. So over time, the meaning has been corrupted, because we are trying to reference to a point we can't really define, once we are moving, so we get lazy and just go by apparent wind. Words are meant to describe or communicate facts. So if we are trying to communicate the direction of sailing, we would have to describe it relative to something that is constant. Apparent wind is not a constant, therefore it doesn't communicate much.

Maybe we could just create some new terms to describe sail trim besides close hauled, that would imply apparent wind. Sail trim angle relative to apparent wind is usually pretty consistent regardless of the boat speed and wind speed.

 

[Kings Gambit]

I think the real problem lies in the fact that even though points of sail refer to boat position relative to true wind, no one really knows for sure what true wind is, unless they have instruments that are calculating it on the fly. Its only one's best guess. So over time, the meaning has been corrupted, because we are trying to reference to a point we can't really define, once we are moving, so we get lazy and just go by apparent wind. Words are meant to describe or communicate facts

I've been reviewing the Sail Trim and Point's of Sail sections (and examining the diagrams) of Sailing Fundamentals by Jobson (copyright 1998), a book touted as the "official" learn-to-sail-manual of the ASA and the USCG Aux. In discussing "Reading the Wind" the author refers to things like how flags are blowing ashore, the direction of smoke blowing from stacks, etc. So, clearly referencing the true wind. Then he says: "The wind is always changing patterns during the day. Use a wind pennant at the top of your mast so you can tell what the wind is doing. This pennant is called the mast head fly." Unless the boat is in its slip, or is anchored, or otherwise not moving, it is now a clear reference to the apparent wind, which is what the mast head fly responds to. This is the beginning of the author's confusion of the two terms, or at least of the reader's confusion. A couple of paragraphs later the author discusses the difference between true and apparent wind, but does not relate either to prior or later references to "the wind."

In the Section on Points of Sail the first one presented is "Sailing Close-Hauled." Also states, "Sailing close-hauled is also known as beating to windward." Here, we have a term that describes the trim of a sail used to define a point of sail: beating to weather, and is so presented as such in the POS diagram on p. 44. However, on the page next to the diagram (p. 45) the author states: "A sailboat's directional heading with respect to the wind is called her point of sail. There are three basic courses: beating (wind is from ahead) reaching (wind is from the side) and running (wind is from astern)."

So, the upwind Point of Sail is beating or perhaps beating to weather, but the diagram and subsequent text inserts the term close-hauled as a synonym for that Point of Sail. All presentation of sail trim depicts or describes sail trim on a given point of sail which is continually referenced to "the wind"; which, considering the big, bold, arrows implies true wind, but showing what could hardly be correct sail trim if the boat were making way. Clearly, a static POS diagram cannot illustrate a POS AND the correct sail trim of a vessel sailing on that POS relative to a true wind. So, the author punts in not specifically indicating which "wind" is being referred to on the diagram.

And the author is evidently aware of this. In an exercise where the student is in a boat at first fixed to the dock with the wind abeam, he has the student trim the mainsail to the true wind, and then writes the following. "Note: As the boat starts to move, the sail will begin to luff again. Don't question it now, just sheet in (pull in the sheet) until the luffing stops." So, as far as the beginning student knows, the sail is properly trimmed to "the wind" as she/he feels it; and this all aligns with the Windex which is pointing the [apparent] wind ahead of the beam as he starts making way, etc. So the student goes almost instantly from a sail trim consistent with a beam reach (when fixed to the dock) to one, according to the illustrations, that might be consistent with sailing on a close reach if there were much wind that day. Now, you have to tell the kid--no, disregard the indications of your Windex and your sail trim set--you're still on a beam reach!!! Whew!--no wonder there is confusion!

 

[Joe]

It is confusing... and that only magnifies the importance of clearly defining which wind one is talking about.

Jobsen and a few others could have avoided this confusion by just stating "when I say "wind" I mean true wind" ... but somewhere along the line they must take the position that that is assumed... and thus the confusion.

It was never clear to me way back when, and it didn't seem to make that much difference.. as is true with many here....

But it was my sailing instructor, when I was taking the Laser class at San Diego State many years ago that pointed it out. We were taking them out into the ocean, tacking out the Mission Bay channel... he came speeding up in his skiff with the mega phone and said... "hey, you caught that wind shift, do you know what happened?" because instead of adjusting my sails.... I tacked on the header and was riding the lift out the channel. The others were concentrating on going all the way across before turning.

At the end of the session... he gathered us together and went through the points of sail again.... stating that our decisions are based on true wind direction... not the wind vane. We can use our close hauled point of sail to detect the wind shifts by watching the line (no compasses on these 14 footers) we sail.... When the fleet was headed you could see everyone's course bending as they followed their wind vane and tell tales... he said "your boat's geometric relationship to the wind direction(meaning true) will define your point of sail" (which is John Rousemaniere's definition) and I'll never forget it.

The muddling of the terms and concept is simply a result of some instruction programs wanting to get their students on the water ASAP. But a conscientious instructor may recognize that making this clear from the beginning will benefit the student in the long run... if he starts racing, for example... or if he's just launching his hobie cat off the beach. True wind will govern his decision.