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#217218 - 08/05/10 05:50 PM light air  
Joined: Sep 2003
Posts: 264
gregP19 Offline
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gregP19  Offline
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Long Island, NY
I have a race on saturday that might have wind in the 5 knot range. I've felt comfortable with my boat speed over 10 knots. In the light air I've felt relatively slow no matter what adjustments I made in sail trim while obviously keeping the weight well forward. I saw the light air post in the general forum but I had a question that I think is more specific for F16 sailors. I've tuned the mast bend according to the Vectorworks manual. Do any of you lighten up on the mast bend when you know the conditions might be lighter than usual? I'm starting to think this is a thoroughbred race horse that wasn't designed to trot. That's ok with me I just want to see if it would help if I loosened up on the diamonds a turn or two. Thanks. Greg


G Gove Blade #728 Long Island, New Yawk
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#217228 - 08/06/10 05:33 AM Re: light air [Re: gregP19]  
Joined: Jun 2001
Posts: 9,582
Wouter Offline
Carpal Tunnel
Wouter  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 9,582
North-West Europe

F16's can be very fast in the light winds as well. I'm too lazy to adjust mij diamonds often and just sail with a good average setting through pretty much the whole season. Light performasnce is however mostly about sail trim and feel and can be rather technical. With big wind it is much easier to find the optimal setting as the response is immediate; in light winds you don't have such a pronounced feedback. Very small adjustments in for example downhaul tension can have large results but you have to wait a 30 seconds before you known it.

It is very easy to kill a modern superwing rig by making the wrong the adjustments. Quite often the right adjustment may eb counterintuitive. Again the example of the downhaul is illustrative. I'm running quite a lot of it in ligh air, more then in medium air and only slightly less then big wind. My mainsail responds well to that but each mainsail may be different in this sense.

Light performance is alot of trial and error and remembering what works for your particular cut of mainsail. Boat by boat testing is very helpful here even when the other boat is a F18 ot N20. You should be able to keep up with both in 5 knots or less wind.

The F18's are hardest to match at about 8-10 knots; not at 5 knots or less or 12 and beyond.

For now I must leave it at that. (I have a full schedule these weeks)

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
#217238 - 08/06/10 08:10 AM Re: light air [Re: gregP19]  
Joined: Jun 2001
Posts: 548
Matt M Offline
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Matt M  Offline
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Joined: Jun 2001
Posts: 548
MERRITTISLAND, FL
Originally Posted by gregP19
I have a race on saturday that might have wind in the 5 knot range. I've felt comfortable with my boat speed over 10 knots. In the light air I've felt relatively slow no matter what adjustments I made in sail trim while obviously keeping the weight well forward. I saw the light air post in the general forum but I had a question that I think is more specific for F16 sailors. I've tuned the mast bend according to the Vectorworks manual. Do any of you lighten up on the mast bend when you know the conditions might be lighter than usual? I'm starting to think this is a thoroughbred race horse that wasn't designed to trot. That's ok with me I just want to see if it would help if I loosened up on the diamonds a turn or two. Thanks. Greg


You can loosen up things, but recognize that at best you are adjusting something that has less than 1% effect on your performance.
Maintaining boat speed in cats is everything. In medium air anyone can make the boat go forward and feel good. Once things get either side of that is where you can see how well you may really be doing.
1. You want to make sure you have a good transition of the mast and sail all the way up the mast. If you have this do not worry any more on the diamonds. Most of the transition is controlled with the down haul adjustment anyway, the diamonds are just the fine tune trim with the gross adjustment being the DH.
2. Make sure you are not over rotating. Much more than about 45 degrees will start to cause drag. If it is wavy and you have to reach to keep momentum in the light stuff, then maybe a little more will be OK, but normally too much make the boat feel sluggish and unresponsive. Sheet to keep the tells in line.
3. Once you have those things covered, it is all about the tiller. Steering the course to keep up the speed is going to be 90+% easy.

#217245 - 08/06/10 10:07 AM Re: light air [Re: Matt M]  
Joined: Sep 2007
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Smiths_Cat Offline
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Smiths_Cat  Offline
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Hamburg
Easing the diamonds reduces the preband, makes the sail fuller (at the same downahul and main tension). Depending on your sail cut, you may or may not want to have a full sail. Probably you may not. More important in light wind is the twist of your sail, hence watch your tell tales.
For me the most important thing and I have always to recall it is that once the boat is going, let it go and concentrate on helm and sheet.

Cheers,

Klaus

#217290 - 08/07/10 12:20 PM Re: light air [Re: Matt M]  
Joined: Aug 2005
Posts: 2,920
PTP Offline
Carpal Tunnel
PTP  Offline
Carpal Tunnel

Joined: Aug 2005
Posts: 2,920
Michigan
how much downhaul for really light stuff? people say leach hook is a speed killer in light stuff and maxing the DH will eliminate that.

#217299 - 08/08/10 04:09 AM Re: light air [Re: PTP]  
Joined: Jun 2001
Posts: 9,582
Wouter Offline
Carpal Tunnel
Wouter  Offline
Carpal Tunnel

Joined: Jun 2001
Posts: 9,582
North-West Europe


For my light air performance is all about reducing draft in the top of my sail (that has lot of draft up there) and leech twist. When I get the settings right the boats starts to accellerate very mildly but maintains this over a long period to arrive at a rather good all-out speed. I only need to be pull in the mainheet a little over this perod (slowly) to keep accellerating.

Of course when I make an error and loose lots of speeds then I have to start over again (with the mainsheet, NOT the other settings). This is the "Feel"-part of light wind sailing. Feeling the chances before they result in lots of loss of speed.

Basically,I gently massage my boat to good speed in light air and in the past I did well in below 5 knots of wind when compared to A's, F18's and Inter-20's. My taipan is actually quite good in such conditions.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
#217304 - 08/08/10 08:59 AM Re: light air [Re: Wouter]  
Joined: Sep 2003
Posts: 264
gregP19 Offline
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gregP19  Offline
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Posts: 264
Long Island, NY
Thanks for all your advice. Our race yesterday went from almost zero wind for 2 hours with the fleet floating with the current to a 15-17knot sea breeze kicking in with a fast fire hose-in-the-face reach in lumpy water for almost 10 miles. The race was 25 miles with half of it in winds less than 5 knots. The few times I could use the spin it wasn't worth it because it acted as a brake in the lulls. I did a horizon job on a Nacra 6.0, Inter 20 and Hobie Tiger. However, an FX one did a horizon job on me. He made it out of the dead zones to the faint wind lines that I saw but just couldn't get to. My mast head windex was of no help because it was spinning 360 degrees as the boat bounced around in the chop. The light winds were oscillating more than 90 degrees. I used to have a bridle fly on my P19 but can't use it on the Blade. At the risk of sounding like a tell tale automaton I think I would have done better with one of those. I had a piece of casette tape tied up front but it got tangled and eventually stuck to the jib making it useless. Is there any type of windex I could use up front for the really light stuff? I'd like to do better in those conditions. I followed Matt's advice regarding the mast/sail transition. Thanks, greg


G Gove Blade #728 Long Island, New Yawk
#217305 - 08/08/10 09:55 AM Re: light air [Re: gregP19]  
Joined: Feb 2005
Posts: 1,382
Jalani Offline
veteran
Jalani  Offline
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Essex, UK
Just put a windex on the tip of your spin pole like the rest of us do.....


Attached Files
Windex.jpg (398 downloads)

John Alani
___________
Stealth F16s GBR527 and GBR538
#217307 - 08/08/10 10:24 AM Re: light air [Re: Jalani]  
Joined: Sep 2003
Posts: 264
gregP19 Offline
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gregP19  Offline
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Long Island, NY
Doesn't it get tangled with the spin during sets and douses? That's what I was afraid of.


G Gove Blade #728 Long Island, New Yawk
#217308 - 08/08/10 10:46 AM Re: light air [Re: gregP19]  
Joined: Feb 2005
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Jalani Offline
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Jalani  Offline
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Essex, UK
No, if you look at the pic you'll see it's underneath the pole and set back from the tip. There's no way that your kite or lines should get back there!


John Alani
___________
Stealth F16s GBR527 and GBR538
#217311 - 08/08/10 11:04 AM Re: light air [Re: Jalani]  
Joined: Jan 2005
Posts: 6,021
Timbo Offline
Carpal Tunnel
Timbo  Offline
Carpal Tunnel

Joined: Jan 2005
Posts: 6,021
Sebring, Florida.
What's wrong with using casette tape on the pole tip lines? That's what I've been doing with all the old ABBA casettes that Ding gave me...


Blade F16
#777
#217786 - 08/18/10 02:30 PM Re: light air [Re: Timbo]  
Joined: Nov 2002
Posts: 612
Steve_Kwiksilver Offline
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Steve_Kwiksilver  Offline
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Posts: 612
Cape Town, South Africa
Light air sailing.. my theory is that a catamaran is actually a monohull with a big place to sit on to weather of it, and the other hull is only there so we can repeat the exercise on the other tack. Thus, if we cannot fly a hull, we should not be sailing. That is my final advice and opinion on light-air sailing.

#217801 - 08/19/10 01:34 AM Re: light air [Re: Steve_Kwiksilver]  
Joined: Jul 2007
Posts: 976
pepin Offline
old hand
pepin  Offline
old hand

Joined: Jul 2007
Posts: 976
France
In light air I've send my crew to the trapeze on the wrong side to get that darn windward hull out of the water... It works, you definitely feel the boat pick up speed.

I've never done it solo, I'm too afraid of the small gust just pushing me over!

#217820 - 08/19/10 08:15 AM Re: light air [Re: pepin]  
Joined: Dec 2008
Posts: 329
TEH Offline
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TEH  Offline
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Posts: 329
Chicago, Illinois USA
I saw the Feldman's do this at Racine to get back in to the beach when there was practically no air, let alone light air. Worked.


Blade F16 USA 725
#217823 - 08/19/10 08:27 AM Re: light air [Re: TEH]  
Joined: Jan 2009
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pgp Offline
Carpal Tunnel
pgp  Offline
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I think that was a reco from Trey.


Pete Pollard
Blade 702

'When you have a lot of things to do, it's best to get your nap out of the way first.

#217825 - 08/19/10 08:34 AM Re: light air [Re: pgp]  
Joined: Dec 2008
Posts: 329
TEH Offline
enthusiast
TEH  Offline
enthusiast

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Posts: 329
Chicago, Illinois USA
Whoever suggested it, it worked. I did not like that tow back in with multiple boats.


Blade F16 USA 725
#217902 - 08/20/10 09:48 AM Re: light air [Re: TEH]  
Joined: Jun 2006
Posts: 98
WillLints Offline
journeyman
WillLints  Offline
journeyman

Joined: Jun 2006
Posts: 98
Santa Fe, New Mexico, USA
Regarding light air, or should I say very light air, Iíve a different opinion than Mark M. This is how I think of it: the air is moving ever so slowly around the lee side of the sail, maybe the speed of an old arthritic man walking with a cane. At that speed I think it nearly impossible for the molecules to separate themselves from the sail surface enough to cause turbulence. As I understand an airplane wing, itís the top of the wing which creates the lift, it is a low pressure created by the curvature of the surface. With our sails, it is the curvature of the lee side of that surface. An airplane with a low stall speed has a wing with a lot of curvature. When a jet lands, especially on a short runway, they extend the rear flaps of the wing and angle them downward so that the plane can fly at a slower speed with out falling out of the sky. Am I right Timbo? So I create the fullest sail I can without changing spreader tension or rake because the wind is a fickle thing. I force the rotator toward the side stay, I loosen the outhaul (very important), let the traveler out 4 inches or so, let the sheet out far enough that the leach is open. My jury is out on the down haul, some times I tighten it and it seems to double my speed, but itís not consistent so I donít how it works. I get on the lee side and that helps, sometimes I get in the trap and that helps a lot in certain wind. As the hull comes out of the water the boat goes faster and the sail generates more lift and I start floating away from the boat with, seemingly, no way back onto the boat, and I capsize. ( I need to train myself to pull on the tiller in those conditions.) These observations are not from sailing a race course but free sailing, sometimes against Hobie.


Will_Lints
one-up, Blade 706, epoxy bottoms

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