Forums > Sailing General

Apparent wind question

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Created by valo > 9 months ago, 23 Jan 2018
valo
NSW, 309 posts
23 Jan 2018 4:52PM
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I have been watching some videos on apparent wind. See this video as an example.



Do you also adjust your head sail, as well as the main, with gusts and lulls in the wind as described in this video?

Thanks

Trek
NSW, 1143 posts
23 Jan 2018 7:10PM
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The goal is to get the maximum lift at anytime. If you are not gunning hard up wind but holding a course trimming the sails is more effective most times than adjusting course which causes drag everytime the rudder moves. If you are pushing hard wind then i found leaving the sails set for that and chasing the windshifts by steering can be better. If the sails are hard on and theres a lull theres less drag and you can coast further than if you eased sail a bit. If you have the man power on board adjusting all sails available is best. Thats my theory. We need a gun racer to comment.

EC31
NSW, 490 posts
23 Jan 2018 7:30PM
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I am not a gun racer, but will put in 1c AUD.

Depends on what you are sailing. Apparent wind sailing is more noticeable in dinghy's, high performance keel boats and multis, where you can quickly adjust the sails (head & main) to the changes in wind direction as your speed increases (or decreases). Frank Bethwaite published some books specifically on the subject (High Performance Sailing & Higher Performance Sailing). Good reading if you are into the technical side of it.

As Trek said,
For a cruising boat going to windward, you will set the head sail snugly up to the side stays and get both sets of telltales (inside & out) flowing. Then bring the main traveller up so the boom is on the centreline and adjust the main so all the telltales (inside & out) are flowing. As the wind changes, you will steer to keep the telltales flowing. While the rudder may act as a brake (especially when a gust hits), it is generally more efficient than adjusting the sails. Serious racing boats will disagree.

For reaching it changes. You try to chase the wind on the sails and not use the rudder. So the crew can't cleat the sheets (or use self tailers) and they tire very quickly. So a lot of cruising boats set and forget and go very slowly on a reach.

Downwind changes back to set and forget and let the skipper do the work with the rudder.

Most cruising boats don't have fast enough crew or equipment to micro adjust as required, so the skipper usually steers the boat up or down to keep the tell tales flowing.

All your sails should have telltales, normally 3 sets on each (top, middle, bottom). I also have a set on each side stay and 2 on the backstay (1 is a very fine piece of cotton for drifters).

MorningBird
NSW, 2660 posts
23 Jan 2018 8:24PM
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Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!

Trek
NSW, 1143 posts
23 Jan 2018 8:31PM
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Select to expand quote
MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!


Crack a beer, feet up

SandS
VIC, 5904 posts
23 Jan 2018 9:05PM
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interesting vid ..... i will try his method of holding course as the wind speed drops . I have always done the opposite of what he is suggesting .
ie take lifts upwind on the gusts ,and steer back down on the lulls, to maintain boat speed .

Ramona
NSW, 7570 posts
24 Jan 2018 8:18AM
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Select to expand quote
MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!


Exactly! The windvane will out steer any gun racing helmsman.

boty
QLD, 685 posts
24 Jan 2018 10:43AM
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Select to expand quote
Ramona said..

MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!



Exactly! The windvane will out steer any gun racing helmsman.


i doubt it windvane or auto is responding to what has happened any decent helmsman is predicting what is going to happen

lydia
1785 posts
24 Jan 2018 8:55AM
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So here goes.
The most important thing to go fast in gusts and lulls is to keep the foils as steady as possible in the water.
This is especially so in waves.
Water is way more dense that air so you trying to keep the keel and rudder as still as possible.
To do this you need CONSTANT ANGLE OF HEEL.
To get constant angle of heel you need to change the direction of the boat.
The rudder however is the very worst way to do this because of drag.
So re-timing however you do is means change in balance and direction to keep constant angle of heel.
In an Etchell for instance, the back stay gets a real working as pulling it on bends top mast flattens mainsail and unloads helm as wind increases.
Conversely, easing softens forestay in waves as wind drops.
But angle of heel remains the same with out any rudder movement.
In chop you can pick the fastest boat in the fleet immediately as it will be the boat that is most steady and stable in the water going upwind.
Hope this does not confuse to many people.
So ignore the telltales and just keep the boat steady.
Telltales are there to help you trim the sails not the boat.
Two very different things.
A modern sportboat will be sailed upwind in plenty with half of the headsail luffing inside out with the sheet very eased.
Otherwise the boat will be so out of balance it will just get knocked flat every gust if you pull the sheet on.
You must always get the balance first.
There is an old saying that the difference between a good and bad driver is that good driver can sail fast upwind with no helm.
Average drivers need to feel of some weather helm to steer the boat uphill.
This holds more true today with high lift low drag foils.
For instance a Sydney 38 is counter intuitative as to get real height you need to get the bow down so the keel loads up more and provides more lift.
So re-trimming the sails is just a function of what you need to make what is under the boat work better.

Chris 249
NSW, 3333 posts
24 Jan 2018 1:28PM
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It's hard to lay down any hard and fast rules that apply across all types. In some classes (ie Laser) top helms often use more helm, or about as much helm, as slow club sailors. When moving in from some other classes one actually has to train yourself off the idea of using minimal helm.

There's also a lot of feedback, no matter what class; if you are better you are more in the groove and therefore may need to use less helm, all else being equal - but in some classes that's as much an outcome of being better as it is a goal.

I still remember watching Kankama blast upwind to one of his championship victories, using more helm and going faster because he was working the boat harder through the waves.

MorningBird
NSW, 2660 posts
24 Jan 2018 2:30PM
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Select to expand quote
boty said..


Ramona said..



MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!





Exactly! The windvane will out steer any gun racing helmsman.




i doubt it windvane or auto is responding to what has happened any decent helmsman is predicting what is going to happen



Have you used a Fleming? Try it, I think you will be pleasantly surprised.
A lot of my crew have commented how it seems to be able to predict what will be needed in the next few seconds. They are quite amazing.
And they don't get tired or use any electricity, food or beer.

frant
VIC, 1230 posts
24 Jan 2018 4:36PM
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Select to expand quote
Chris 249 said..
It's hard to lay down any hard and fast rules that apply across all types. In some classes (ie Laser) top helms often use more helm, or about as much helm, as slow club sailors. When moving in from some other classes one actually has to train yourself off the idea of using minimal helm.

There's also a lot of feedback, no matter what class; if you are better you are more in the groove and therefore may need to use less helm, all else being equal - but in some classes that's as much an outcome of being better as it is a goal.

I still remember watching Kankama blast upwind to one of his championship victories, using more helm and going faster because he was working the boat harder through the waves.


I would tend to disagree. Little or no helm is faster and better laser sailor the less rudder used for steering. Downwind its all in the foot pressure leeward to come up and roll to windward to bear away. The tiller follows the turn. Similar upwind where torquing is used to steer. Exception is that strong rudder may accompany the torque if slamming into a wave is going to be slower than using the rudder as a steering brake.
Big dump of mainsheet when gust hits to both keep the boat flat and for apparent wind moving aft, then trim on as boat speed moves apparent forward. I disagree with the upwind hold course and coast concept. Essentially to hold maximum vmg you have to sail and trim fatter in lighter wind requiring a bear away.

valo
NSW, 309 posts
24 Jan 2018 5:40PM
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Thanks everyone for taking the time to answer.
I have a lot to learn!
MUST DO MORE SAILING!!

Chris 249
NSW, 3333 posts
24 Jan 2018 9:45PM
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Select to expand quote
frant said..






Chris 249 said..
It's hard to lay down any hard and fast rules that apply across all types. In some classes (ie Laser) top helms often use more helm, or about as much helm, as slow club sailors. When moving in from some other classes one actually has to train yourself off the idea of using minimal helm.

There's also a lot of feedback, no matter what class; if you are better you are more in the groove and therefore may need to use less helm, all else being equal - but in some classes that's as much an outcome of being better as it is a goal.

I still remember watching Kankama blast upwind to one of his championship victories, using more helm and going faster because he was working the boat harder through the waves.








I would tend to disagree. Little or no helm is faster and better laser sailor the less rudder used for steering. Downwind its all in the foot pressure leeward to come up and roll to windward to bear away. The tiller follows the turn. Similar upwind where torquing is used to steer. Exception is that strong rudder may accompany the torque if slamming into a wave is going to be slower than using the rudder as a steering brake.
Big dump of mainsheet when gust hits to both keep the boat flat and for apparent wind moving aft, then trim on as boat speed moves apparent forward. I disagree with the upwind hold course and coast concept. Essentially to hold maximum vmg you have to sail and trim fatter in lighter wind requiring a bear away.


It's steering to avoid the exceptional slam that I was referring to, although in the sloppy area between Sydney Heads it's not too "exceptional." I completely agree with your remarks about downwind sailing and mainsheet use. I'm also comparing good Laser sailors to slow club sailors who tend to be very inert.

n my very brief serious Laser career I took the NSW champs overall and Masters against a guy who'd been 4th in the open worlds and the three-time world champ in my Masters division, so can't have been getting it too wrong. I can remember watching Michael Blackburn and listening to KK (who has a better record than mine) and then specifically going out to practise using MORE helm. Yep, it's odd, but it works in slop, and guys like Tom Slingsby use a lot of helm.

Edit - for instance, at 24:20 and following, look at silver (?) medalist Bouwmiester (sp) waggling away in quite moderate conditions here;


Pavlos Kontidos, another silver medallist, waggling away from 18:11 here at


The club level sailors I've coached are nothing like that aggressive on the helm. Yes, in other classes (ie Tasar) it's normally the other way around.

Ringle
NSW, 188 posts
25 Jan 2018 10:08AM
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Select to expand quote
boty said..

Ramona said..


MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!




Exactly! The windvane will out steer any gun racing helmsman.



i doubt it windvane or auto is responding to what has happened any decent helmsman is predicting what is going to happen


Yes but the windvane doesn't look around, or light a cigarette or regale us with stories of great conquests with women whilst losing concentration on steering. It just doggedly steers for hours and days on end. On average it steers upwind pretty well.

Kankama
NSW, 671 posts
26 Jan 2018 10:15PM
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Select to expand quote
Ramona said..

MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!



Exactly! The windvane will out steer any gun racing helmsman.


Sorry but this is totally incorrect, a good helm react to waves before they reach you, will be watching for gusts and lulls before they arrive and as stated above will be changing apparent wind angle depending on how the boat is handling the conditions. A vane can never predict and no serious race boat would use a vane if they had a pretty average helm.
Sailing with apparent is tricky. Even with our 38 ft performance cruising cat I often don't head to my destination but sail the best angle instead. Setting a course and forgetting can happen more on lower performance boats but it can pay to alter course downwind even on a traditional mono. There is a huge amount to proper steering technique and hard and fast rules about setting a particular course will sometimes be on error.
For example, on Kankama, if I steer just 10 degrees higher sometimes I can more than double my speed, through extra apparent, but in more breeze the difference is less. Listen to the boat and learn what it is telling you.

PhoenixStar
QLD, 477 posts
26 Jan 2018 10:11PM
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Select to expand quote
Kankama said..

Ramona said..


MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!




Exactly! The windvane will out steer any gun racing helmsman.



Sorry but this is totally incorrect, a good helm react to waves before they reach you, will be watching for gusts and lulls before they arrive and as stated above will be changing apparent wind angle depending on how the boat is handling the conditions. A vane can never predict and no serious race boat would use a vane if they had a pretty average helm.
Sailing with apparent is tricky. Even with our 38 ft performance cruising cat I often don't head to my destination but sail the best angle instead. Setting a course and forgetting can happen more on lower performance boats but it can pay to alter course downwind even on a traditional mono. There is a huge amount to proper steering technique and hard and fast rules about setting a particular course will sometimes be on error.
For example, on Kankama, if I steer just 10 degrees higher sometimes I can more than double my speed, through extra apparent, but in more breeze the difference is less. Listen to the boat and learn what it is telling you.


"Listen to the boat" is what it is all about. If you have a wind instrument coupled to your GPS check out your VMG. Almost always you will get higher VMG if you are pinching up and sacrificing some boat speed. The optimum angle can be surprisingly narrow. Wind vanes are great cruising gear but if you cant do better to windward than a wind vane you really should get in some more helming practice.

sirgallivant
NSW, 1531 posts
26 Jan 2018 11:39PM
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Races last a few hours and concentrating on the helm is a strenuous business hence at the VOR the helm is changed hourly in rough conditions.

In other single handed races like Atlantic crossings they use sophisticated auto pilots because it would be impossible to helm 24/7.

The vane is a cruising tool.

One shouldn't compare apples with oranges.

Helming is one of the most strenuous, obnoxious occupation on a yacht, ever.
No wonder, cruisers generally don't fancy helming.

Kankama
NSW, 671 posts
27 Jan 2018 7:44AM
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Using apparent cleverly is often poorly done by sailors. One example I commonly see is when people struggle to roller furl the headsail when sailing close to the wind. If you are sailing at 4 knots to windward in 15 knots you get an apparent of about 18 knots. If you do a quick turn to a square run and do 5 knots you get an apparent of 10. Because force is proportional to velocity squared the force required to furl the heady is reduced to about a third. Use the apparent for good instead of evil.

Ramona
NSW, 7570 posts
27 Jan 2018 9:12AM
Thumbs Up

Select to expand quote
PhoenixStar said..

Kankama said..


Ramona said..



MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!





Exactly! The windvane will out steer any gun racing helmsman.




Sorry but this is totally incorrect, a good helm react to waves before they reach you, will be watching for gusts and lulls before they arrive and as stated above will be changing apparent wind angle depending on how the boat is handling the conditions. A vane can never predict and no serious race boat would use a vane if they had a pretty average helm.
Sailing with apparent is tricky. Even with our 38 ft performance cruising cat I often don't head to my destination but sail the best angle instead. Setting a course and forgetting can happen more on lower performance boats but it can pay to alter course downwind even on a traditional mono. There is a huge amount to proper steering technique and hard and fast rules about setting a particular course will sometimes be on error.
For example, on Kankama, if I steer just 10 degrees higher sometimes I can more than double my speed, through extra apparent, but in more breeze the difference is less. Listen to the boat and learn what it is telling you.



"Listen to the boat" is what it is all about. If you have a wind instrument coupled to your GPS check out your VMG. Almost always you will get higher VMG if you are pinching up and sacrificing some boat speed. The optimum angle can be surprisingly narrow. Wind vanes are great cruising gear but if you cant do better to windward than a wind vane you really should get in some more helming practice.


A good windvane especially to windward will easily out helm the best helmsman about. That's why they are banned from racing use!

shaggybaxter
QLD, 2526 posts
27 Jan 2018 9:01AM
Thumbs Up

Select to expand quote
Ramona said..


PhoenixStar said..



Kankama said..




Ramona said..





MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!







Exactly! The windvane will out steer any gun racing helmsman.






Sorry but this is totally incorrect, a good helm react to waves before they reach you, will be watching for gusts and lulls before they arrive and as stated above will be changing apparent wind angle depending on how the boat is handling the conditions. A vane can never predict and no serious race boat would use a vane if they had a pretty average helm.
Sailing with apparent is tricky. Even with our 38 ft performance cruising cat I often don't head to my destination but sail the best angle instead. Setting a course and forgetting can happen more on lower performance boats but it can pay to alter course downwind even on a traditional mono. There is a huge amount to proper steering technique and hard and fast rules about setting a particular course will sometimes be on error.
For example, on Kankama, if I steer just 10 degrees higher sometimes I can more than double my speed, through extra apparent, but in more breeze the difference is less. Listen to the boat and learn what it is telling you.





"Listen to the boat" is what it is all about. If you have a wind instrument coupled to your GPS check out your VMG. Almost always you will get higher VMG if you are pinching up and sacrificing some boat speed. The optimum angle can be surprisingly narrow. Wind vanes are great cruising gear but if you cant do better to windward than a wind vane you really should get in some more helming practice.




A good windvane especially to windward will easily out helm the best helmsman about. That's why they are banned from racing use!



Yep, I reckon they're not too shabby! I have no experience with windvanes so cannot speak, but quality auotpilots are amazing. They're receiving all the telemetry 25 times a second , as compared to my old Raymarine ST1000 which was once per second, and the volume of telemetry is nuts, roll, yaw, pitch (so the pilot can react to wave action) as well as all the heel angle, rudder angle, wind , gps and water data, it's pretty incredible how good they are.
I've noticed even in foul conditions that the helm movements appear more economical than us humans seem to do, embarrassingly I'll randomly flick over to auotpilot now and then to see if I'm oversteering the boat! A good pilot makes trimming the boat a joy too, you trim till the autopilot is moving merely an inch or two.
An autopilot working hard, and this is with a broken foil too.

Edit: have a look at the 3 min mark for a great example of burying the nose under full noise under autopilot, pretty cool.

Ramona
NSW, 7570 posts
27 Jan 2018 5:59PM
Thumbs Up

Excellent video. Catamarans and planning monos don't use windvanes because the rapid acceleration shifts the relative wind too suddenly. This has led to the superb and expensive autopilots mainly from France.

SandS
VIC, 5904 posts
27 Jan 2018 7:15PM
Thumbs Up

so was the reason he wasn't clipped on because he new the helicopter would save his life if he was washed overboard ?

or his he always that much of a risk taker ?

Kankama
NSW, 671 posts
29 Jan 2018 6:55AM
Thumbs Up

An autopilot or vane can never steer as well as a good helmsman because they can't anticipate or change gears.

In the case of a vane, you lock in the apparent wind angle you want the boat to steer to, but a really well sailed boat will change apparent angle, in small amounts, all the time.

Downwind, you wander about to steer down the face of waves, and the fastest sailors I have raced against wander really cleverly. Downwind is often where they are much faster than their competitors. In my Laser career I was pretty fast in Australia downhill but once was passed by a Brazilian (Peter Tanschiet) who swished rather than forced his boat around. Getting off the wave early was the trick. Tanschiet won a worlds later on. The Australian who won the 87 worlds moved his boat around a lot as well, the trick was to do it in harmony with the waves and using clever amounts of sheet and roll. Even in yachts you will wander to avoid sailing uphill as much as possible. Watch the Volvo vids and see how the helms are actively steering to get the boat pointing nose down and avoid ploughing into the uphill water ahead.

If you listen to the talk on board Oracle in the finals of the AC you will hear Tom Slingsby (5 time world Laser champ) talking about different modes. You will hear "high mode" "low mode or bow down" and "VMG mode". What he is instructing the helm to do is to sail slightly different angles upwind for small periods of time. You hear the same talk in the Volvo boats. What these guys are doing is altering the apparent to engage different gears. As well as the tactitian talking, you will hear the main trimmer (Langford) talking as well. He steers the boat almost as much as the helm.

First gear is when you are stopped and want to get going. Going upwind you ease sheets, get the leeches twisted and sail an angle that almost stalls the leeward telltales. This gets the boat up to speed and then you can go to second gear. Apparent is aft a bit of normal.

Second gear is when are trucking along. Windward and leeward telltales are streaming and you have cranked the sheets and vang in. The leech and foot are curved but straighter than first gear. Apparent is at probably 28-30 degrees. Then more wind comes in and you got to

Third gear where you are past max righting moment. So you start heading into the wind slightly. The windward telltales lift and the ease some main traveller and the luff of the main is luffing for 10-20 % of its girth. Apparent is forward more. Then the wind comes in more and you go to fourth gear.

Now you don't care what the luff is doing, you steer up to keep the boat on its feet. You could reef but you bleed off pressure by getting the main and jib luffing and you may even be sailing just on the back half of each sail. Headsail leads out wide, traveller down, backstay hard on.

In a race, you may shift gears with every large gust and lull or major phase in longer events, traveller up and down, from second to third and back to first when you hit waves. Shifting apparent back and forth depending on sea state and wind speed. The good racers anticipate these transitions and look at the breeze so they can anticipate their required moves. A well sailed boat flows and is in a constant state of flux. You can't lock in a required angle and get optimum performance.

Mike Fletcher was an Olympic coach and wrote the article that first got me into gear changing. It was a revelation because it helped me make sense of what I felt. In races you can often have lots of the fleet have similar speed but when people have to change gears, the better sailors cruise through because the slower sailors don't transition as well.

For us when we cruise we have to ease back on the work required. But it is good to know about modes and changing gears and shifting apparent. I still do it, even when cruising, but I just do it less regularly.

Chris 249
NSW, 3333 posts
29 Jan 2018 12:05PM
Thumbs Up

Select to expand quote
Ramona said..



PhoenixStar said..




Kankama said..





Ramona said..






MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!








Exactly! The windvane will out steer any gun racing helmsman.







Sorry but this is totally incorrect, a good helm react to waves before they reach you, will be watching for gusts and lulls before they arrive and as stated above will be changing apparent wind angle depending on how the boat is handling the conditions. A vane can never predict and no serious race boat would use a vane if they had a pretty average helm.
Sailing with apparent is tricky. Even with our 38 ft performance cruising cat I often don't head to my destination but sail the best angle instead. Setting a course and forgetting can happen more on lower performance boats but it can pay to alter course downwind even on a traditional mono. There is a huge amount to proper steering technique and hard and fast rules about setting a particular course will sometimes be on error.
For example, on Kankama, if I steer just 10 degrees higher sometimes I can more than double my speed, through extra apparent, but in more breeze the difference is less. Listen to the boat and learn what it is telling you.






"Listen to the boat" is what it is all about. If you have a wind instrument coupled to your GPS check out your VMG. Almost always you will get higher VMG if you are pinching up and sacrificing some boat speed. The optimum angle can be surprisingly narrow. Wind vanes are great cruising gear but if you cant do better to windward than a wind vane you really should get in some more helming practice.





A good windvane especially to windward will easily out helm the best helmsman about. That's why they are banned from racing use!




As KK noted they can't anticipate waves and gusts. All the best steerers are watching incoming waves and gusts and anticipating them. Every good Laser or Windsurfer sailor, for example, spends hours sailing in a straight line, working how to luff the boat through gusts without straying from the ideal angle of heel, which means watching each gust to assess its strength, while also bearing off to roll through a bad patch of waves, sailing higher in a flat spot, or steer the boat around an individual crest. In big boats, even AC crews have someone calling the seconds down to each gust, to allow the driver to anticipate it without taking their eyes off the bow, where they are steering the boat over the waves in the way a wave cannot.

As another example, there's an enormous number of incidents where people have said that it was harder to sail in a pitch black night because they could not see incoming swells and wind. If it was all about reacting rather than anticipating, that wouldn't be the case.

Downwind it's even more important in some ways. If you get hit by a bad gust in some boats without bearing away beforehand, the extra heel will spin the boat into a broach no matter what the rudder does after the gust hits.

valo
NSW, 309 posts
29 Jan 2018 12:31PM
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Select to expand quote
Kankama said..
An autopilot or vane can never steer as well as a good helmsman because they can't anticipate or change gears.

In the case of a vane, you lock in the apparent wind angle you want the boat to steer to, but a really well sailed boat will change apparent angle, in small amounts, all the time.

Downwind, you wander about to steer down the face of waves, and the fastest sailors I have raced against wander really cleverly. Downwind is often where they are much faster than their competitors. In my Laser career I was pretty fast in Australia downhill but once was passed by a Brazilian (Peter Tanschiet) who swished rather than forced his boat around. Getting off the wave early was the trick. Tanschiet won a worlds later on. The Australian who won the 87 worlds moved his boat around a lot as well, the trick was to do it in harmony with the waves and using clever amounts of sheet and roll. Even in yachts you will wander to avoid sailing uphill as much as possible. Watch the Volvo vids and see how the helms are actively steering to get the boat pointing nose down and avoid ploughing into the uphill water ahead.

If you listen to the talk on board Oracle in the finals of the AC you will hear Tom Slingsby (5 time world Laser champ) talking about different modes. You will hear "high mode" "low mode or bow down" and "VMG mode". What he is instructing the helm to do is to sail slightly different angles upwind for small periods of time. You hear the same talk in the Volvo boats. What these guys are doing is altering the apparent to engage different gears. As well as the tactitian talking, you will hear the main trimmer (Langford) talking as well. He steers the boat almost as much as the helm.

First gear is when you are stopped and want to get going. Going upwind you ease sheets, get the leeches twisted and sail an angle that almost stalls the leeward telltales. This gets the boat up to speed and then you can go to second gear. Apparent is aft a bit of normal.

Second gear is when are trucking along. Windward and leeward telltales are streaming and you have cranked the sheets and vang in. The leech and foot are curved but straighter than first gear. Apparent is at probably 28-30 degrees. Then more wind comes in and you got to

Third gear where you are past max righting moment. So you start heading into the wind slightly. The windward telltales lift and the ease some main traveller and the luff of the main is luffing for 10-20 % of its girth. Apparent is forward more. Then the wind comes in more and you go to fourth gear.

Now you don't care what the luff is doing, you steer up to keep the boat on its feet. You could reef but you bleed off pressure by getting the main and jib luffing and you may even be sailing just on the back half of each sail. Headsail leads out wide, traveller down, backstay hard on.

In a race, you may shift gears with every large gust and lull or major phase in longer events, traveller up and down, from second to third and back to first when you hit waves. Shifting apparent back and forth depending on sea state and wind speed. The good racers anticipate these transitions and look at the breeze so they can anticipate their required moves. A well sailed boat flows and is in a constant state of flux. You can't lock in a required angle and get optimum performance.

Mike Fletcher was an Olympic coach and wrote the article that first got me into gear changing. It was a revelation because it helped me make sense of what I felt. In races you can often have lots of the fleet have similar speed but when people have to change gears, the better sailors cruise through because the slower sailors don't transition as well.

For us when we cruise we have to ease back on the work required. But it is good to know about modes and changing gears and shifting apparent. I still do it, even when cruising, but I just do it less regularly.



I might have to find someone that races like this and see if I can tag along and watch and learn.
Interesting reading. Thanks.

shaggybaxter
QLD, 2526 posts
29 Jan 2018 1:07PM
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Chris 249 said..

Ramona said..




PhoenixStar said..





Kankama said..






Ramona said..







MorningBird said..
Cruising, set the sails for maximum efficiency, engage wind vane steering, kettle on!









Exactly! The windvane will out steer any gun racing helmsman.








Sorry but this is totally incorrect, a good helm react to waves before they reach you, will be watching for gusts and lulls before they arrive and as stated above will be changing apparent wind angle depending on how the boat is handling the conditions. A vane can never predict and no serious race boat would use a vane if they had a pretty average helm.
Sailing with apparent is tricky. Even with our 38 ft performance cruising cat I often don't head to my destination but sail the best angle instead. Setting a course and forgetting can happen more on lower performance boats but it can pay to alter course downwind even on a traditional mono. There is a huge amount to proper steering technique and hard and fast rules about setting a particular course will sometimes be on error.
For example, on Kankama, if I steer just 10 degrees higher sometimes I can more than double my speed, through extra apparent, but in more breeze the difference is less. Listen to the boat and learn what it is telling you.







"Listen to the boat" is what it is all about. If you have a wind instrument coupled to your GPS check out your VMG. Almost always you will get higher VMG if you are pinching up and sacrificing some boat speed. The optimum angle can be surprisingly narrow. Wind vanes are great cruising gear but if you cant do better to windward than a wind vane you really should get in some more helming practice.






A good windvane especially to windward will easily out helm the best helmsman about. That's why they are banned from racing use!





As KK noted they can't anticipate waves and gusts. All the best steerers are watching incoming waves and gusts and anticipating them. Every good Laser or Windsurfer sailor, for example, spends hours sailing in a straight line, working how to luff the boat through gusts without straying from the ideal angle of heel, which means watching each gust to assess its strength, while also bearing off to roll through a bad patch of waves, sailing higher in a flat spot, or steer the boat around an individual crest. In big boats, even AC crews have someone calling the seconds down to each gust, to allow the driver to anticipate it without taking their eyes off the bow, where they are steering the boat over the waves in the way a wave cannot.

As another example, there's an enormous number of incidents where people have said that it was harder to sail in a pitch black night because they could not see incoming swells and wind. If it was all about reacting rather than anticipating, that wouldn't be the case.

Downwind it's even more important in some ways. If you get hit by a bad gust in some boats without bearing away beforehand, the extra heel will spin the boat into a broach no matter what the rudder does after the gust hits.


Really interesting, all good and pertinent points from all. The following point of view is from Jesse Naimark-Rowse, an Imoca 60 techo genius from Osprey, and Bob Congdon, a NKE techo genius.

"However, autopilots can't see or anticipate windshifts or off-?kilter waves and react ahead of time like a human helmsman. "From my experience in waves, particularly upwind slamming, the pilot struggles to match a good helmsman," says Naimark-Rowse. "In flat water, a good autopilot steering to a wind angle can be so precise that it's hard for a helmsman to match it."
Congdon agrees. "Any condition that's difficult for a human is hard for a computer," he says, noting that NKE incorporated two new modes - Gust mode and Surf mode - in the Processor HR to help the autopilot compensate. "If the autopilot is told to steer a course of 135 degrees true-wind angle and the computer realizes it's in a puff, it might need to go up to 140 degrees for a moment to keep both the speed up and the boat on it's feet (Gust mode). The computer recognizes the conditions and reacts before a broach."

Kankama
NSW, 671 posts
29 Jan 2018 5:05PM
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That's very interesting Shaggy

shaggybaxter
QLD, 2526 posts
29 Jan 2018 6:33PM
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Hi Kankama,
Glad you think so! I'm particularly interested primarily so I know how far I can trust my autohelm. I'm also noting the innovation that is being developed seems to have the desired reliability as well as the techy cool. What I want more than anything in my autohelm is reliability. Crash gybes aren't fun on any day in any condition.
The Surf mode the NKE tech refers to is for when you rapidly decelerate off the back of a surf, it dynamically alters helm response so you mitigate all that kite flappy thingy bit when you fall off off the back of the wave/surf. The mini 6.5's report good results with the software mod with no hiccups, and I reckon those guys would find any bugs.

Bastardising the OP's original question a bit, and replace the driver with an autohelm brings an interesting observation for me.... I've set the autopilot to AWA downwind under kite a couple of times, it's really nice, less work for the trimmers. The helm calmly slaloms the boat down the course as the boat speed varies, holding the same heel angle. The course over ground suffers though as it's in long looping runs. Probably not good for attempting to lay a mark, but a very nice way to sail!
If I set the autopilot to TWA mode we're going to be trimming the boat more, as the autohelm only accepts True Wind changes, not boat speed changes. So changes in boat speed in TWA mode requires trimming more, but you'll lay that mark easier.
When we're racing, upwind or downwind we (should be) trimming non stop, always chasing that constant heel angle. Sometimes we get lazy, and you see the difference.

boty
QLD, 685 posts
30 Jan 2018 8:59AM
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rule no 1 on yachts gadgets will always let you down the more gadgetry the more it lets you down wind vanes are the simplest method of self steering but will never think to flick the bow off before it gets to the top of the wave
for those who race on any class of boat you always put your best helmsman on in difficult conditions and im pretty sure i wouldn't put the auto on in 35 knots with the kite on or my windvane (which i rarely use only because i don't like the clutter on deck ) . Though the moment the engine goes on i always engage the auto and often when cruising it is on i just accept the loss in performance as time for making cups of tea or baking



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"Apparent wind question" started by valo