Trimming the jib on a bream reach

[Bill Roosa]

I'm finding myself agreeing with KG on this on. The usefulness of POS is to describe the various things you have to contend with when setting sails. The last two words being the key. I do not set my sails according to the true wind. Therefore, the POS diagram is not drawn to reflect true wind. Course it does not address the fact that the apparent wind changes as you proceed through the different POS either and I think that is where the confusion is. it only has one "wind arrow" which would imply true wind not apparent. However, as I stated before, the usefulness of the diagram is in providing a lexicon so it is easy to talk about the common things you have to deal with on the various POS. it was never intended to provide SPECIFIC facts about how the wind and your boat interact related to boat velocity and wind speed.

Another way of saying this is the POS diagram shows how to coarsely set you sails, amidships when “beating” (see I used one of the words to simplify what I’m trying to describe), athwart ships when “running” (and again). Which brings us full circle because if the POS diagram is in fact showing us how the sails are generally set then it must be talking about the apparent wind. Otherwise the diagram is wrong and I would not be on my fastest POS when on a broad reach. Joe would have me on some other POS due to the boat and wind speed. And that would make your fastest POS something other (in all cases) than a broad reach.

Sorry Joe. I don’t disagree with any of your concepts as to why and how apparent and true wind are related or what you can use them for however.

 

[RichH]

I think you all are missing the point of true wind vs. apparent wind as the the set/trim/shape of the sails greatly affects the angle 'apparent wind' ... all due to the 'upwash' of oncoming wind towards the sails. The 'upwash' is the deflection of air ... just because the sail is 'there' and the amount of deflection is due to the 'shape', and relative speed, etc. of the sail. And yes, most of the 'wind flow diagrams of the airflow stream-lines' you see in 'sailing books' are usually wrong with respect to 'upwash'.

 

[Joe]

What, is that a joke? Somebody with 25 yr of sailing and racing experience doesn't know how points of sail work? Actually, I think it is the opposite in this case.

What we've been discussing is the definition of a point of sail. All the material you have referred me to basically says what both of us have been saying--heading of the boat relative to THE WIND direction. Your articles say only "THE WIND." The issue at hand is WHAT WIND? I say it's the APPARENT WIND, you say it is the TRUE WIND. In my definition, "THE WIND" is ALL OF THE WIND that the boat experiences when it is moving. In yours, it's only the wind the boat experiences before it begins moving. In my definition, the POS and the sail trim are directly related; in yours the POS and sail trim are not related (just refer to your own comments above).

If anyone is confused it's someone (you) who doesn't sail enough or is not observant enough to know that a wind gust moves the apparent wind aft if a boat is sailing close hauled (or on any POS except running). I wonder if your boat even has a Windex on it; somehow I doubt it. You are misled by the diagrams which are static, simplified, representations of a sailing concept that an instructor is trying to present to a beginner student; in practice it's more complicated than that. Nevertheless, you cannot even interpret them. You're saying that if a sailing vessel is trimmed for wind coming at 90 deg abeam (i.e., where the diagram clearly says "beam reach"), it's really not a beam reach; it's really a broad reach b/c the true wind must be coming from a greater angle? That, in my opinion is nonsensical.

My point is, and always has been, that your point of sail is based on your course across the wind, true...not apparent... Because you can't have a course across apparent wind.... apparent wind is a result of your course and your boatspeed interacting with true windspeed and direction. Doesn't that make sense?

Therefore, doesn't it make sense that using apparent wind direction to define your point of sail is inappropriate because your AWD can change while the vessel maintains the same course across the same wind direction?

To me is makes perfect sense... and I'm a 65 year old freak. You don't need 25 years of experience and a windex to understand this... But it is a great revelation when you do, no matter how long you've been sailing.

Ask yourself this.... if a high speed catamaran is sailing on a beam reach at 20 kts in moderate winds, what is its Apparent wind direction reading? Do you think it's sitting on 90? HELL NO... it's probably like 20. So do you say it's closehauled, when it's really 135 degrees off the true wind....... of course not. It's on a beam reach.... no matter what the AW indicator says. Do you think that same boat can sail close hauled at 20 degrees to true wind because the indicator says the AW direction is 20... NO WAY.

You must use true wind direction when discussing a point of sale.

 

[RichH]

So Joe, what is the true wind direction as defined in the attachment pic shown in post #22?

 

[Bill Roosa]

Well Joe explaining it the way you did in your last para in post #23 just does not make sense. What I take away from that is I will never know what point of sail I'm actually on since I typically don't have access to the true wind direction. If I have no standard way of talking about being on a, for instance, a beam reach then what is the use of this term? If a beam reach can be any apparent wind from 0 to 180 degrees due to boat speed and wind speed why even talk about POS. It only makes sense to use the term to describe the direction that the apparent wind is coming from because I always set my sails to that wind. using apparent wind lets me reference a specific wind direction that is the same (beating, broad reach, beam reach) all the time and everybody knows what I'm talking about.

I guess I don't understand how using true wind is helpful to describe the boat on a specific POS. I can't set my sails to it, I can't use the term to describe what the boat is experiencing. It makes the term(s) useless (to me)

 

[Joe]

So Joe, what is the true wind direction as defined in the attachment pic shown in post #22?

Rich, that attachment does not define true wind direction. That simply shows air flowing around a set of sails. True wind is independent of the boat..... it is the wind that exists when you stand on the dock longingly admiring a passing yacht. True wind direction and velocity are the same, whether you are standing or moving. The difference is, you cannot feel the true wind while you are on a moving boat. That's why they have conversion charts and forumlas, or computerized instruments, that give you that information so you can make tactical decisions or plan your cruise on the most comfortable point of sail.

Rich, please understand that I am not arguing true vs apparent wind when it comes to sail trimming. To a man, we all use Apparent wind to dial in our sails. I use the telltales and wind indicator just like everyone else. I shape my sails with AWD and AWS being the primary factor.

No, the genus of my point is that only two factors define a point of sail. The true direction of the wind and the boat's course(or position) relative to this wind. Other than gross settings, true wind data has little to do with how you trim the sails..... we rely on apparent wind data and our senses for that.

Why are we broaching this subject? Because this thread's original poster was concerned that he couldn't get the tell tales to fly correctly when on a 90degree beam reach. I simply contributed that "beam reach" is a point of sail relative to true wind direction and that he may actually be sailing further off the wind if he was using apparent wind data to define his point of sail.... which would explain the difficult performance of his telltales. He responded that he was 90 degrees off true..... which is a beam reach, so we move on to the next solution.... Unfortunately, someone said I was wrong in my definintion of "points of sail"...... and here we are.

 

[Joe]

Well Joe explaining it the way you did in your last para in post #23 just does not make sense.

Sorry.

What I take away from that is I will never know what point of sail I'm actually on since I typically don't have access to the true wind direction.

One of the easiest ways to determine the true wind you're sailing in is to sail closehauled on port and starboard tack.... note the compass headings... then average the two. example Port tack 315m, starboard tack 225m, average heading is 270m degrees.

If I have no standard way of talking about being on a, for instance, a beam reach then what is the use of this term? If a beam reach can be any apparent wind from 0 to 180 degrees due to boat speed and wind speed why even talk about POS.

Reaching....(close, beam and broad) or sailing across the wind covers about 120 degees of the 180. Determine your true wind as I mentioned above, then look at your boat's compass heading.

It only makes sense to use the term to describe the direction that the apparent wind is coming from because I always set my sails to that wind. using apparent wind lets me reference a specific wind direction that is the same (beating, broad reach, beam reach) all the time and everybody knows what I'm talking about.

That's cool..... but think of the apparent wind as not "coming" from somewhere, but the true wind being "affected" by other elements....

we normally setup our sails initially in anticipaton of a particular point of sail we intend to pursue. We head upwind on a close reach with the boom and jib pulled inboard..... then we turn downwind and let the boom and jip out, ease the backstay and outhaul, set a spinnaker etc..... all this is done without having to look at the windex or instruments..... we know that when we change a point of sail there will be basic adjustments. Then as the boat picks up speed after the change in direction....we observe the apparent wind data to maximize performance.

So... yes... we use the apparent data to maximize performance by either triming the sails or changing course..... but.. we always think of the wind direction outside the boat when we make tactical decisions. Anything else is just sailing back and forth trying to go fast but not really caring where we go....heh,heh... Yikes. guilty, your honor, coming from an old beach cat sailor.

I guess I don't understand how using true wind is helpful to describe the boat on a specific POS. I can't set my sails to it, I can't use the term to describe what the boat is experiencing. It makes the term(s) useless (to me)

I think you use it without thinking about it.... like when you know that you can tack and clear an obstacle. You're using your knowledge of the boat's tacking angle to guide you in that decision. You know this because you know how close your boat can sail to the true wind direction for various conditions.... and this translates into a sense of the tacking angle you need to clear the mark. You don't look at your apparent wind device when you make this decision... it is not about the sail trim, it is about the boat's position relative to the true wind.....and the mark.

Anyhow...... Sorry I've ruffled some feathers........ I just wanted to help.

 

[Joe]

apology

..... When sailing upwind, an increase in windspeed will cause the APPARENT wind direction to move FORWARD, not aft....

Folks, this statement is totally incorrect on my part. An increase in BOATSPEED will cause the AWD to move forward, but and increase in WINDSPEED moves the apparent wind aft!!!! My apologies to Mr King's Gambit.

 

[Bill Roosa]

I think determining the true wind by pressing the true wind button is a whole lot easier. if you have a raymarine wind instriment and tie it to the gps this (and lot of other data) is avalable with just the touch of a button.
Still don't think the POS diagram is based on true wind. The thing is just useless if it is. I mean really, what does it tell you if it is based on the true wind? it does not provide a common language to describe what the wind is doing to the boat as it coud be either and (apparent wind) beat or DDW run. Since I'm pretty fond of saying "I was beating all to heck ......." and most understood that that ment the apparent wind was coming from somewhere near the bow Iguess I've been misleading folks. Actually what was happening was I thought I was beating but did not take into account that the boat and wind speed ad effected the apparent wind and ........... so what point of sail am I on? (question to myself) Heck I can't tell directly so how can I explain to folks what is happening in some easy rational fashion that does not require them to do vector math?
Well I just use apparent wind and then everything is simple. I'm on a beat means something specific that everybody understands.

 

[Cayennita]

Always maximize VMG (Velocity Made Good) upwind and minimize downwind when racing w/l courses. Raymarine instruments give you this. A GPS will give you VMG to a mark or a waypoint. Even Dennis Connor only cared about VMG. We sailed into irons at the starting line and check true wind direction and at the same time see if the weather mark is left or right of the bow and is the line square. Then Sail close haul on both port and STB. Now you have all the information you need. Add to that what is the wind doing every 5 minutes. This gives information on where you want to start on the line unless you are planning on going after a particular competitor. Also will tell you what to do when rounding the top mark.

 

[Kings Gambit]

Folks, this statement is totally incorrect on my part. An increase in BOATSPEED will cause the AWD to move forward, but and increase in WINDSPEED moves the apparent wind aft!!!! My apologies to Mr King's Gambit.

Accepted; but here it is again (post 13). If sailing close hauled you are by definition sailing as close to the wind as the boat will sail w/o entering the no go zone (see your diagrams). At this point, I suppose you could choose whichever wind you like in thinking about it, however illogical. But, if there is a gust (w/o a change in true wind direction), and the apparent wind moves aft a few degrees, the boat is no longer sailing close hauled for the period of the gust b/c it is no longer sailing as close to the wind as it was a few moments prior--i.e., no longer meeting the definition of close hauled. Thus, on that same true wind direction the boat could be sailing close hauled or sailing not close hauled in a given interval of time (w/ constant heading). Since that POS is variable on constant true wind direction, true wind direction CANNOT DEFINE IT! By similar reasoning, true wind cannot define the other POS either, and we are led to the conclusion that only the apparent wind can define a boat's point of sail w/o ambiguity.

 

[Stu Jackson]

Geez, this is getting mind-numbing.

In a gust you head up, so you still stay close hauled.

What's so hard?

 

[Bill Roosa]

KG said it better than I did.

 

[Bill Roosa]

But Stu, when sailing down wind in a gust you bear off if you want to maintain the POS
up in the puffs and off in the lufts (upwind)
off in the puffs and up in the lufts (downwind) Course that would ignor the fact that nobody ever does that as there is no "in irons" going downwind

 

[Kings Gambit]

Geez, this is getting mind-numbing.

In a gust you head up, so you still stay close hauled.

What's so hard?

If you change your heading (i.e., head up in a gust) to remain close hauled, you are changing your heading to maintain a certain POS w/o a change in the true wind direction. At that moment, any supposed "definitional relationship" of POS between the boat's heading and the true wind direction falls apart. Conversely, if you head up to remain close hauled with the change in the direction of the apparent wind, then your heading relative to the APPARENT WIND is defining your POS.

 

[Joe]

If you change your heading (i.e., head up in a gust) to remain close hauled, you are changing your heading to maintain a certain POS w/o a change in the true wind direction.

Yes....you are trying to stay as close to that true wind direction as possible. A change in true wind direction does NOT change the close hauled angle, while all the other factors you've mentioned will. Therefore, unless you make sail trim adjustments to compensate, a change in true wind direction will force a change in your compass heading, i.e. lift or header.

At that moment, any supposed "definitional relationship" of POS between the boat's heading and the true wind direction falls apart.

No.... the boat's closehauled angle merely changes.. from one number to another...as long as the boat is sailing closehauled it is still on the same point of sail. The constant here is the true wind direction... we can't change that... but we can control the apparent wind direction by altering course... so you must express your ability to sail close hauled in terms on the one thing you can't control... the true wind direction.

Conversely, if you head up to remain close hauled with the change in the direction of the apparent wind, then your heading relative to the APPARENT WIND is defining your POS.

Aha!... do you see? You have confused a heading, or compass course, with APPARENT WIND ANGLE. Your apparent wind indicator doesn't know what compass course you're sailing.... How does an apparent wind angle define the relationship between a boat's compass course and the compass direction of the true wind?.... it can't.... because you are a great sailor and you can control the apparent wind angle. But you aren't good enough to control the true wind direction....not without some unearthly help.

 

[Bill Roosa]

Joe! We love you man but you are clearly not getting it. I'm ok with that cause sailing is fun and this kind of debate is just that, a debate. At the end of the post we are still friends.
So let me see if I'm getting what you are saying correctly:
when I'm on a beam reach the true wind is 90 degrees off the bow and the apparent wind could be from any direction? This assumes a boat with some pretty high performance figures but this is all hypothetical so lets just go with it.
If I could get the boat going fast enough the apparent wind would go far enough forward and I would (gee I don't have a word for it now as I'm still on a beam reach) have to have the sails trimmed in tight and the boom amidships etc. If I hit a killer tide and the true wind was not that strong then it is conceivable that I could have the boat (again I don't have a word for what is happening as I'm still on a beam reach in your definition) with all the sail "let out" and the boom out over the water.
Do you see what I mean. I can't even describe what is going on using your concept.

Care to explain using your terminology???

 

[cwkemp]

Joe said:
"I think you use it without thinking about it.... like when you know that you can tack and clear an obstacle. You're using your knowledge of the boat's tacking angle to guide you in that decision. You know this because you know how close your boat can sail to the true wind direction for various conditions.... and this translates into a sense of the tacking angle you need to clear the mark. You don't look at your apparent wind device when you make this decision... it is not about the sail trim, it is about the boat's position relative to the true wind.....and the mark.

Anyhow...... Sorry I've ruffled some feathers........ I just wanted to help "

Joe, I definitely see the concept you are trying to explain here regarding tacking strategy, and I must admit making silent calculation for tacking based on estimation of the true wind, though not so precisely as a racer equipped with electronics might make. The debate on the semantics will probably go on, but I do see your principle and acknowledge a real-world application.
As for my feathers, none ruffled. We're all cool.
Clint

 

[Joe]

Joe! We love you man but you are clearly not getting it. I'm ok with that cause sailing is fun and this kind of debate is just that, a debate. At the end of the post we are still friends.
So let me see if I'm getting what you are saying correctly:
when I'm on a beam reach the true wind is 90 degrees off the bow and the apparent wind could be from any direction? This assumes a boat with some pretty high performance figures but this is all hypothetical so lets just go with it.
If I could get the boat going fast enough the apparent wind would go far enough forward and I would (gee I don't have a word for it now as I'm still on a beam reach) have to have the sails trimmed in tight and the boom amidships etc. If I hit a killer tide and the true wind was not that strong then it is conceivable that I could have the boat (again I don't have a word for what is happening as I'm still on a beam reach in your definition) with all the sail "let out" and the boom out over the water.
Do you see what I mean. I can't even describe what is going on using your concept.

Care to explain using your terminology???

Yeah Bill..... I hear ya... You're sailing closehauled with true wind 90 degree off the bow.... how the hell are you going to get that boat upwind to the mark?

Actually you've provided a good example of why defining your point of sail with apparent wind direction can be misunderstood. The boat in your example is pretty much always sailing close hauled.... but... if you slow the boat down the apparent wind will move aft and you can alter your course further upwind with the lift. So, in your example, the apparent wind angle really isn't very useful.... but if you could compare boatspeed with the angle the boat is sailing to true wind (TWA) Then... you could use that information to get somewhere.

Sorry this is so short, but its late and I still have to drive down to San Diego tonight.

 

[Bill Roosa]

Joe, gotcha!
How can I be sailing close hauled (that is a POS) with the ture wind 90 degrees off the bow (your definition of beam reach POS). I can't be on both POS at the same time can I?
I can get to boat up wind to the mark just like the ice racers do. Their low drag and resulting high speed allows them to tack to the mark. now all I need is a higher performance boat. But that misses the point

BTW your statement "You're sailing closehauled with true wind 90 degree off the bow" is exactly how I'd relay it. I'm sailing closehauled (to the apparent wind) with the true wind 90 degrees off the bow.

Also, I'm thinking that you are restricting your conversation to racing issues and I'm not. I'm decussing the term POS and what is its definition. Not how do I get to the upwind mark.