Proper use of outhaul

Jul 5, 2005
217
Beneteau 361 Sandusky Harbor Marina
Hi folks,

During the off season I've been trying to read more about tactics to improve my team's racing performance. I viewed a Youtube video by someone named PPConsultant, who had another video in a different thread recommended by Jackdaw (thanks JD) which I found very informative. He had a video on proper use of the outhaul too, but it left me with a question he hadn't answered.

In heavy air, PPConsultant recommended tensioning the outhaul to flatten the sail, which I have been doing.

In light air, he recommended easing the outhaul completely to increase draft and subsequently lift, which I've been doing, buy maybe not enough.

In very light air (under 3 knots), he recommended setting the outhaul midway between where we set it in heavy air and where we set it in light air. I had read this before and have practiced this in our racing.

My question is this, in the "light air" conditions, how do you know if you've eased the outhaul TOO MUCH? My concern is that if we put too much curvature on the sail the wind flow will detach. Will misbehaving leech telltales let us know if the outhaul is eased too much and when the air flow has detached?

Sorry if this is rudimentary, but I've always just "winged it" before when racing. But now I'm on a friend's boat and we started winning this past year, and we're all trying to graduate from Noob status. We sail a Ranger 26.2.

Thanks so much for any advice!
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Correct, if you ease the out-haul too much in light air, the flow will detach from the BACK of the sail, and the telltails will stop flying and usually fold back.
 
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Oct 19, 2017
7,733
O'Day 19 Littleton, NH
Based solely on my limited knowledge of fluid dynamics, sailing small boats as a kid, and limited logical conjunctions. I would suggest that increasing camber in lighter air to improve lift is fundamental and well understood. I have no doubt you don't have any trouble with that. In really light air, the issue becomes something more physical, mechanical, practical? Not so much about fluid dynamics as about rig behavior when lift is too light to hold everything in good position. If the sail is left too baggy you get more flogging. The sail doesn't have air support to maintain shape. Tightening up the sail forces it to maintain a better shape. Not the ideal shape but, better.
The downhaul and vang in conjunction with a preventer would also help, I should think.
- Will (Dragonfly)
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Based solely on my limited knowledge of fluid dynamics, sailing small boats as a kid, and limited logical conjunctions. I would suggest that increasing camber in lighter air to improve lift is fundamental and well understood. I have no doubt you don't have any trouble with that. In really light air, the issue becomes something more physical, mechanical, practical? Not so much about fluid dynamics as about rig behavior when lift is too light to hold everything in good position. If the sail is left too baggy you get more flogging. The sail doesn't have air support to maintain shape. Tightening up the sail forces it to maintain a better shape. Not the ideal shape but, better.
The downhaul and vang in conjunction with a preventer would also help, I should think.
- Will (Dragonfly)
No, even with the sail held in shape with gravity (crew weight leeward), in very light air, flow can detach from the back sides of foils and generate little lift but lots of drag. Flattening the sail is the solution.
 
Jan 1, 2006
7,040
Slickcraft 26 Sailfish
I sail with the outhaul fully tight in very light air. It was taught to me, probably by Speed Smarts, that very light wind cannot stay attached to the sail with too much camber in it.
How much tension is the trick. I was once advised to put tell tails on the main about 1/3 of the way back and up a couple of feet. I could imagine that they would tell you when you lose flow in that area. My sailmaker sail they would be stalled all the time and I never did put them on.
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
I seldom chime in when Jack talks about trimmings sails
But...
On my 13 ton "Tub" in light air, [I have all the sail trim gadgets], it would make zilch difference.
So...
It depends a lot YOUR boat design on the best adjustment.
Jim...

PS: I have topping lift, adjustable vang, Leach tensioner, Traveler, Main sheet, infinite reefing and Outhaul.
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
There doesnt appear to much consensus.

Ive been following up on Arvel Gentry's work in the 70's.
Does AG actually say something that disagrees with what I posted? If so I'm interested, and can you quote it?
 
Jan 1, 2006
7,040
Slickcraft 26 Sailfish
... it would make zilch differenc...
I'm not sure about that. The right camber might not make the boat scream upwind but I'd bet it would make a measurable difference. So maybe it's only a half knot. On a sunset sail with light wind that could be a big difference. It could be the difference between the sailing foils working or not. One version is sailing the other is drifting around.
 
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Arlo Davy Guthrie is an American folk singer-songwriter. Like his father, Woody Guthrie, he is known for singing songs of protest against sailboat outhaul injustice. Guthrie's best-known work is his debut piece, "Alice's Restaurant Reef Points", a satirical talking blues song about 18 minutes in length that has since become a Thanksgiving anthem. (just making sure 'yer paying attention)
 
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Oct 19, 2017
7,733
O'Day 19 Littleton, NH
One of my favorites
All about protest and sailing.
:liar:
Well, maybe not exactly.
- Will (Dragonfly)
 
Apr 16, 2017
841
Federation NCC-1701 Riverside
Does AG actually say something that disagrees with what I posted? If so I'm interested, and can you quote it?
Not sure, you usually have excellent skillz & and experiences so i wouldnt expect to find much. Did you want me to try?

I dont think he talked about the outhaul anymore than say a traveler or backstay. As a beginner, its tempting to snatch up simple concepts like when in doubt let it out and so forth. Easy button technique most of us can apply.

When i look around the rules for outhaul are something like sheet in for heavy wind, let out for slow wind, but not all the way out cause then you detach the airflow, unless you need power to get out of waves. If rounding up flatten sails, etc. Another poster pulls it in tight no matter what, i bet theres a badass who sailed a schooner round the horn of mexico and didnt know there was an outhaul.

Seems the answer to these sail shape/trim queztions is to find the best placement for telltales, then really pay attention and get those flowing correctly.

I suspect that if the main is trimmed in but it seem impossible to keep the telltales near the trailing edge attached, it might be time to put some tension on the outhaul. If telltales look perfect then maybe let it out some to take advantage of lifting opportunities.