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      Abbreviated rules   07/28/2017

      Underdawg did an excellent job of explaining the rules.  Here's the simplified version: Don't insinuate Pedo.  Warning and or timeout for a first offense.  PermaFlick for any subsequent offenses Don't out members.  See above for penalties.  Caveat:  if you have ever used your own real name or personal information here on the forums since, like, ever - it doesn't count and you are fair game. If you see spam posts, report it to the mods.  We do not hang out in every thread 24/7 If you see any of the above, report it to the mods by hitting the Report button in the offending post.   We do not take action for foul language, off-subject content, or abusive behavior unless it escalates to persistent stalking.  There may be times that we might warn someone or flick someone for something particularly egregious.  There is no standard, we will know it when we see it.  If you continually report things that do not fall into rules #1 or 2 above, you may very well get a timeout yourself for annoying the Mods with repeated whining.  Use your best judgement. Warnings, timeouts, suspensions and flicks are arbitrary and capricious.  Deal with it.  Welcome to anarchy.   If you are a newbie, there are unwritten rules to adhere to.  They will be explained to you soon enough.  
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Kevin Hall, one of the best and successful nice guy sailors ever, gives you plenty to think about...

“Mr. Herreshoff agreed that computers provide certain information about a boat's performance and the action of the wind, but a ''super sailor will sense a lot of other things - all those nuances that exist in your mind after 20 years of sailing.'' In an age of winged keels, plastic sails and black boxes in the cockpit spewing out digital data, it is comforting to know that the feel of the wind on the cheek still counts.” Read more.

Sailing is so cool. You can do it in a tiny boat with no instruments. You can do it in a huge boat with lots of instruments. You can enjoy the subtle challenges on big boats around whether the instruments are helping – they must be! It says “TRUE” right on the display! – or hurting: well, Bob, it seems like every time we sail target speed we just dribble into the boat to leeward and don’t go forward much at all….

Here is a fact: we are using fundamental concepts and hardware from circa 1987 on the most cutting-edge keelboats in the world. While the way we use them now is highly evolved, what we are using has barely changed in over thirty years. Perhaps my biggest lament in my sailing career is that I never got to sail with Juan Vila or Stan Honey to see how they do it. (Most of the rest of us are just bluffing and hoping nobody notices!) While you and I may never get to sail together either, I can certainly jot down a few things I’ve noticed going on between sailing instruments and their end users, and hope your time reading about those things feels well spent.

In this multi-part series, I’ll share a little of my experience as a racing navigator and AC testing manager. You will come away with a better understanding of your instruments as fundamentally flawed tools. These tools can help win races if working well and used as one of many types of input. However, they can also mislead if they are working poorly. Even trickier, they can be “working perfectly” on a synoptically unusual day and give terrible advice. Advances in technology make some dreams about a new way to do the whole thing worth considering. I’ll share my personal vision for this in the final article.

For now, we will assume that everything is calibrated perfectly. Not because that is a reasonable assumption, but because we’re going to geek out enough without worrying about calibration.

Fluids and fields. The boat moves through and disturbs a what-you-see-is-what-you-get fluid, evidence of which we can easily see – bow waves, or a wake which betrays things like resistance and leeway. We can easily measure, or reliably model, the angle to centerline of the water moving under the boat. We can easily measure, and reliably calibrate, the velocity of the water moving past the boat. Now we have everything the instrument system needs to know about what’s going on down there.

Basically, we measure boatspeed and do something about leeway, and get on with it. If for some reason, we sailed in a place where there was 6 knots of current going one way at the bottom of the keel and 4 knots of current going sideways to that at the boatspeed sensor depth, and 2 knots headed somewhere 30 degrees different again at the waterline, it would be much harder to decide what to call leeway or boatspeed. Fortunately, that sort of thing is very rare.

The sailplan also moves through a fluid, called air. Also three dimensions. Harder to see, but there are things like luffing sails, and tipping boats to remind us some forces are at play. Here’s where the rubber comes right off the road and goes on vacation: we still sample that highly dynamic field in one place, do some trigonometry, and call it “truth”, just like we did in 1987.

Emirates Team New Zealand owns a data set from an America’s Cup Act in 2005 in Malmo, Sweden which will help make the point. I ran around after navigating a day’s racing saying “hey, guys, you should see the data! We sailed all day without ever tacking! It says right here in the data!!” The sweaty, exhausted grinders looked at me like I had a propeller, or something, coming out of my forehead. Of course we had tacked – the boat tipped left, it tipped right. The genoa snapped in on the port side, then the starboard. But meanwhile, the “TRUE wind angle” volleyed from -80, to -10, and back again. “Ah! Well, that must have been quite a lot of Shear!” I hear some of you saying. I guess the water was really cold, or Thor’s hammer was spinning backwards, or something that day.

The instruments told one version of the story, as measured way up high in the sky, while far below, the telltales told a different story. On that particular day, it was easy to walk away from the TRUTH, because down on deck it was so obviously a lie.

Let’s pretend for the rest of the article that God decides there is never again directional shear, in either hemisphere, in reality or in the instruments’ depiction of that reality. One problem with 1987-but-also-2017 would be solved. There’s still another problem. You know how some days the water is almost glassy but the boat tips right over and sails anyway? That’s “Wind Weight” or “Wind Profile”. It behaves with regard to our instrument system and historical data something like this: “Compared to an average day, a heavy windweight wind is pushing in total on the sails more than the number we are calling ‘TRUE wind speed’ says it should.

By contrast, a light windweight wind is tipping us over less than the windspeed says it should”. That glassy day, the windspeed measured only at the top of the rig would output a number much higher than one suggested by the seat-of-the-pants sailor looking only at the water to choose a jib code before hoisting sails. Sails would go up, sailing heel would be compared to historical averages of target heel for that windspeed, and target boatspeed would be reduced by the trimmers and helmsman to reflect the lower wind weight day.

You might hear things onboard from the old salts like “the wind really isn’t filled down to the water today” and, soon after, “let’s start with target a knot under posted”. On boats with more elaborate systems and reliable historical data, you might hear “Heel WindWeight 80%” (where Heel WW = Heel/Target Heel reverse-looked-up as windspeed) and then “Heel WindWeight target eight tenths under posted”. With any luck, this would happen before coming off the start line and dribbling into the boat to leeward.

Here’s where it gets good: using live heel compared to historical heel creates a feedback loop. So, if we suspect a lower wind weight day and adjust our target speeds down just a little, our averages are shaded toward less actual heel from sailing slightly thinner on the telltales, which corroborates the lower wind weight. Without a boat to leeward of us creeping ahead with a better mode, we could easily talk ourselves with data into sailing way too high and slow. The same happens in reverse: we suspect strong wind weight so we sail pressed, the average heel numbers go up so we gain confidence in higher wind weight, etc.

Many keelboat classes have lots of practice using excellent data but, also, boat on boat relatives. Then, these feedback loops have balancing additional information coming from other boats to help find what really works and avoid spiraling toward poor performance which the data says is good.

Now, check this out! There is a secondary feedback loop for targets in the 1987-but-also-2017 system. If we decide to shade our sailing toward the narrow/high-mode side of targets, and before even changing course we trim our sails ever-so-slightly tighter, the mainsail with reduced twist bends the windfield narrower ahead of it and the windvane reports that we are sailing higher. So, the upwash on the tighter mainsail causes the “TRUE wind angle” to read (artificially!) slightly narrower just from the trim change. Similarly, if we shade our sailing toward the wider/fast mode side of targets, the more-twisted sail upwash causes the “TRUE wind angle” to read artificially slightly wider just from the trim change.

Splitting hairs, “artificially” narrow TWA causes the TWS to under-read, artificially wider TWA causes the TWS to over-read. So now we have data which says the tighter-sail-lower-heel-super-high-mode is working even better, because not only have we shifted the baseline of the TWS lookup slightly to show us performing well in “less wind”, we have also made the wind angle read over-narrow. When this “tighter-higher test” is compared with the “looser-wider test” (where the instruments over-sold the windspeed and over-widened the wind angle), it’s a double double smackdown for the high mode.

So you know how I said “God said no more shear”? He was kidding. Have a look at the above paragraph again, but imagine what starts to happen when we cause the input to the entire system (measured at one point) to have actual, real-world asymmetry. Now you’ve got a TWS which is part of a wind-triangle solution measured at one point but in a wind-field which is actually bent from the deck to the masthead.

So, that TWS reads as higher on the wider tack, and the faster targets derived from looking up a target boatspeed from that TWS is added to the mix. So you respond to those targets by sailing more pressed…and…tacking away. But now the shear is making the targets under-read, and you can’t understand why you were lower and not much faster on the other tack sailing target, but now you’re higher and much much slower and just got rolled. You tell yourself you’re doing this for fun, but….

Phew. We’ve gotten to the top mark debating the authority of the targets, theorizing about where the errors might come from when they don’t seem to work right against the other boats, and wondering whether maybe the label for the wind angle displayed on the mast shouldn’t be something more like: “Representation of angle of the sailplan to a 3-dimensional field, sampled in one place, itself influenced by said sailplan and also invisibly variable in time and across the course, which we boil down to one number and egregiously misname as ‘True’”.

Later, we can go downwind and try to figure out what to do with our target boatspeed and TWA numbers, when they assume use of the tiller and crew weight to create dynamic apparent wind speed and dynamic apparent wind angle behavior which keeps the downwind heel and kite trim matching those assumptions.

For now, a quick summary: it’s way more complicated than it looks from a stack of six displays on the mast, of which two say “TRUE” and another one screams “Target” like it owns the place. We are still bringing a spatula to a lightsaber fight. The reason the very top boats don’t notice how dated their instruments are, is that they have gone to great effort and expense to add multiple, autonomous interlaced neural nets boasting highly-evolved, experience-assimilating algorithms and richly nuanced communication protocols to their onboard systems.

We call those: sailors. Title inspiration thanks to XTC.

 

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There has to be some analogy here to quantum physics but I haven't quite figured it out -- still early in my coffee.  Something along the lines of if you try to measure it, you'll change the result.

Schrodinger might appreciate it.  Keep trimming the sails tighter, sailing higher and with less heel -- the numbers look great.  But the cat is dead :(

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Well, I am having my Friday nite rums, so it should be going into my head; the theory, not the rum as that is going somewhere else, so if there aint gonna be an exam later I'll have another rum......

Cheers,

Jim :wacko:

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I heard a good spot to measure direction, that's relatively un influenced by sail flow is off the tip of the windward spreader.  Sounds convenient?

 

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2 hours ago, mromberg said:

There has to be some analogy here to quantum physics but I haven't quite figured it out -- still early in my coffee.  Something along the lines of if you try to measure it, you'll change the result.

 

This guy Heisenberg gave it a pretty good try.

https://en.m.wikipedia.org/wiki/Uncertainty_principle

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Simpler: learn how to sail boats without displays. If/when you later move to boats with data available then you may choose to use the data to augment your decision making - or not. Gauge-focus capitulates poor seamanship.

 

Vis a vis the brain bleeder above - how about offering some application: How much more performance could enhanced knowledge of the live 3D wind environment offer a 6ktsb? Or ETNZ in BDA?

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That's actually the older 2D analog model that many people prefer because of its phenomenal battery life. You do have to give up the built-in illumination though.

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I stopped using my instruments about 6 months ago - had a short somewhere so I turned the system off and found that I did not miss any of it. Maybe depth but w/o depth I found myself acting more responsibly and not simply hoping for the best

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9 hours ago, dan@electramed.ie said:

My head hurts ....

^^^^ditto!

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45 minutes ago, IStream said:

That's actually the older 2D analog model that many people prefer because of its phenomenal battery life. You do have to give up the built-in illumination though.

Not in the daytime...

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Well, its nice to know how fast you're going, to have something to talk about in the bar.  So I really like a good speedo.  (Except, of course, on the older, larger and hairier of our species.)

But all the best sailors I've sailed against (and they are very, very good) don't give much credence to secondary calculated functions such as TWA and TWS...if they even have those functions on board.  If you can't figure out what sail to use by looking at the water and going tippy, you are in trouble.  Boat speed, depth, GPS charts and data, masthead fly and they are good to go.

Of course, we're in an area that has many geographical wind shifts, large tidal currents and complicated topography/bathymetry.  So, head out of the boat is the way to go.

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yea I got a headache too. this made putting in deicers this morning seem like fun..

evan  though the other idiot lost the map where everything goes. Wasn't Heisenberg

the meth guy on breaking bad

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14 hours ago, Editor said:

The reason the very top boats don’t notice how dated their instruments are, is that they have gone to great effort and expense to add multiple, autonomous interlaced neural nets boasting highly-evolved, experience-assimilating algorithms and richly nuanced communication protocols to their onboard systems.

I surmised this:

1.  The instruments and data are flawed.

2.  Sail more.

3. Go with your gut.

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4 hours ago, EvaOdland said:

I have a 3d display at the masthead...it points where the wind is coming from....

 

s-l300.jpg

Nah.  Upwash upwash upwash.  Or something.

That said, I enjoyed this one, looking forward to the next episode.

TOG

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5 hours ago, HFC Hunter said:

Simpler: learn how to sail boats without displays. If/when you later move to boats with data available then you may choose to use the data to augment your decision making - or not. Gauge-focus capitulates poor seamanship.

 

Vis a vis the brain bleeder above - how about offering some application: How much more performance could enhanced knowledge of the live 3D wind environment offer a 6ktsb? Or ETNZ in BDA?

From my experience, it is as important to know "when" to use the instruments as is "how" to use the instruments.  Kevin illustrated many examples of when the instruments won't tell you what you need to know.

Assuming they did tell you what you needed to know, ie a 3D wind-field, you would still need someone who knows how to trim the sails to maximize the efficiency of the rig, and you would need a tactician/navigator to get you to the place on the course that makes best use of the wind patterns....

I find that the instruments are useless to the novice sailor, to get to say 80% efficiency, you need some time on the water, and a feel for the wind.  To get you to 95% takes a good crew, and lots of practice.

To get that last 5% requires a little bit more knowledge, and that may come from the instruments (or from hiring a pro or local expert).

I sail PHRF these days, so don't have the opportunity to use other boats to give feedback on our relative speed.  We have to use the boat's targets as a guide to how we are doing.  I log all our races, and improve our targets after each race (yes, using 1987 technology).  

So, to answer the questions, how much does technology offer a 6ksb?  It really depends on your starting point (i.e. are you good enough to use the data), and do you need the data (ie, if you are sailing one design, you will get better feedback from your nearby competitors that you would from any instrument  system).

Not sure if I answered anything but that's my 2 cents...

 

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5 hours ago, IStream said:

That's actually the older 2D analog model that many people prefer because of its phenomenal battery life. You do have to give up the built-in illumination though.

Wireless technology.

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In over 30 years in this field this is one of the best essays on the subject I've ever seen. I would argue that the systems and theory's used on today's high end race boats really started a little earlier, circa 1984 or so when Ockam got going. Dick McCurdy and Art Ellis should be in the sailing hall of fame. That said, everything we use today is based on their pioneering work.

Ockam gave us Upwash corrections, however bludgeon like they were applied at the time. B&G added a downwind speed correction and the WTP gave us dynamic motion correction. All dating to the late 1980s.  More recently the B&G WTP and the NKE Regatta and HR processors have refined these early principles to let a sophisticated operator give his crew a truly spectacular wind direction solution but if I was starting from scratch today with a good budget I would be seriously looking at the Sailmon products. And if I was much younger and not retired i would probably be working for them.

But in the end it boils down to these four things. Where am I on the race course? How hard is the wind blowing? How fast am I going?  Where is the wind coming from?  

Kudos to Kevin Hall for this and to the ed for printing it.

 

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3 hours ago, BobC said:

Kudos to Kevin Hall for this and to the ed for printing it.

Awesome article, nice to see someone discussing vertical wind profile and interaction in relation to not just instruments, but on feel.  Tapes and tales are still elite tools with varying degrees of shear and its turbulent byproducts nearly always present.    Your dad's old box of unlabeled vhs tapes from the 80's is still good for something.

 

telltales.jpg

vhs.jpg

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Well worth the brain hurt.

Yes, sailors who rely solely on instruments are akin to those who follow their car GPS instructions into embarrassment or  disaster. On the other side, instruments are not distracted by the need for sudocrem or blood alcohol levels. 

Yet, instruments like the Vendee autopilots are now essential. 

Too, you can't teach student drivers using geometry and mathematics to test if they can figure out how much to turn the wheel when using a freeway on ramp, in icy conditions, at varying speeds. Put  'em behind the wheel and they'll figure that out without any math skills. 

Anyway, was stuck on "wind weight". (Is Kevin Hall the same Kevin Hall who wrote Black Sails White Rabbits: Cancer Was the Easy Part?) 

If "wind weight" is the term being used to describe the up/down force of the wind, not just the direction, that seems to help. "Upwash" also works. So, a 3D problem, not 2D

Sailors  learn to 'see' the invisible in 3D from the shape of a cloud, colour of water.  2D might work to introduce a concept in a classroom, but is pretty limited on the water. Surprised that more of our instruments and 'weather maps' haven't evolved so 3D is the default.

Compasses are gimballed, so maybe the wind instruments need to measure upwash and downdraft too so that the TW can be measured in 3D. 

Vendee autopilots are pretty successful--nay, essential.

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11 hours ago, HFC Hunter said:

Simpler: learn how to sail boats without displays.           

 

 

No surprise that K Hall was a great Laser sailer. 

Plain and simple - some guys got the race won while the rest of us are still figuring out the favored side.

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Something not mentioned, when you are shopping for a used boat, having an array of working instruments is desirable...

I say this as I remember the dead B&G Hercules instruments still occupying spaces the bulkhead....I would remove them but  the old instruments make a happy smiley face with the inclinometer I put in...

It is good to have a happy boat.

IMG_4674.JPG

Screenshot from 2017-12-02 06-41-25.png

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19 hours ago, southerncross said:

I surmised this:

1.  The instruments and data are flawed.

2.  Sail more.

3. Go with your gut.

More like, the instruments are a tool. The more you understand how your tool works, the better you can use it. On the most successful programs I've worked with, the trimmer calls the target for the leg each time, based on data both observed and collected 

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16 hours ago, stief said:

Well worth the brain hurt.

Yes, sailors who rely solely on instruments are akin to those who follow their car GPS instructions into embarrassment or  disaster. On the other side, instruments are not distracted by the need for sudocrem or blood alcohol levels. 

Yet, instruments like the Vendee autopilots are now essential. 

Too, you can't teach student drivers using geometry and mathematics to test if they can figure out how much to turn the wheel when using a freeway on ramp, in icy conditions, at varying speeds. Put  'em behind the wheel and they'll figure that out without any math skills. 

Anyway, was stuck on "wind weight". (Is Kevin Hall the same Kevin Hall who wrote Black Sails White Rabbits: Cancer Was the Easy Part?) 

If "wind weight" is the term being used to describe the up/down force of the wind, not just the direction, that seems to help. "Upwash" also works. So, a 3D problem, not 2D

Sailors  learn to 'see' the invisible in 3D from the shape of a cloud, colour of water.  2D might work to introduce a concept in a classroom, but is pretty limited on the water. Surprised that more of our instruments and 'weather maps' haven't evolved so 3D is the default.

Compasses are gimballed, so maybe the wind instruments need to measure upwash and downdraft too so that the TW can be measured in 3D. 

Vendee autopilots are pretty successful--nay, essential.

Wind weight in that article is a way to describe the "punch" in the wind.  It is a combination of wind speed, temperature and relative humidity as temp/humidity changes the kinetic energy (you can call it driving force) for a certain wind speed.  The reason is that the density (weight of a certain volume) of the air changes with temp and humidity - cold, dry air is much heavier than hot, humid air and thus provides more "drive" for the same wind speed

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19 minutes ago, Christian said:

Wind weight in that article is a way to describe the "punch" in the wind.  It is a combination of wind speed, temperature and relative humidity as temp/humidity changes the kinetic energy (you can call it driving force) for a certain wind speed.  The reason is that the density (weight of a certain volume) of the air changes with temp and humidity - cold, dry air is much heavier than hot, humid air and thus provides more "drive" for the same wind speed

Ah, got it. Thanks for taking the time for the clear explanation. Off to read more about the limitations of  Dynamic Pressure

That might also clear up a comment made by a fellow sailor at CORK back in 1977. He was dreaming of a sail laminate that would change colours depending on the pressure on different parts of a sail. :)   Another itch scratched, thanks to SA.

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3 hours ago, Meat Wad said:

Instruments we use on my boat

speedpuck-featured-image_600x600.png

shift-featured-image_600x600.png

PlastimoIrisHBCHockeyPuck.jpg

compucourse-musto-400.jpg

 

You forgot the universally most important instrument for racing sailboats...

12278538.thumb.jpg.bbd5f5e8b656988bbe038ca7cb5e3dfc.jpg

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Somewhat off topic (well. sailor girl liked it), wonder how much this success story is due to engineers, math, and tech vs gut feelings and seat-of-the-pants. I think Kevin Hall would like it too, from what I've been able to read about him.

 

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20 hours ago, Varan said:

You forgot the universally most important instrument for racing sailboats...

12278538.thumb.jpg.bbd5f5e8b656988bbe038ca7cb5e3dfc.jpg

 

I think a start watch goes without saying.

The Shift has a real nice timer built in, so the crew can see the time and it can sync to any whole minute.
 I also wear a Optimum Time Series 3 that I bought way back for the 2.4mR racing.
Both have real big numbers and audible signals if needed.


Several crew members also have their watches.

I am a minimalist and have slowly been removing crap off the boat since I took ownership.

 

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