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Slow in light wind

Posted By: Mpls_Nacra

Slow in light wind - 07/14/14 04:49 PM

Hello, all I am relatively new to racing. I just got my Nacra F16. I find that when racing in light wind I am extremely slow. I keep thinking I am over sheeting and over pointing, but I am not so sure of that any more. I'd really appreciate some tips on how to improve boat speed. (I am sitting far forward, I allow the mast to rotate most of the way out) I am sure there is more I can do.

thanks for the advice.
Posted By: Mike Fahle

Re: Slow in light wind - 07/15/14 01:07 AM

Are you using leech tell tales? The best way to know if you are over sheeting is to watch the tell tales on the leech (each one attached at the edge of the material). As long as they are flowing (indicating attached air to the leech) then you have not over sheeted. Once you do, the leech tells will cease flowing as the sail loses attached airflow and will swirl behind the sail or just droop. There should be at least two tell tales on the leech - one in the bottom third to indicate traveler trim and one in the top third to indicate mainsheet trim. Regarding trim in light air, follow the old saying, "When in doubt, let it out". Once the sail is eased and you sail a bit lower, gently trim in and adjust course accordingly until the leech gets too tight according to the tell tales and then ease back out a bit to get the flow going again. This applies downwind as well as upwind. In light air it is more likely that leech twist will need to be increased as there is likely to be more wind shear, especially the lumpier the water gets. More twist also gives the sail a wider groove but if the water is flat and the wind is pretty steady then sheet in as long as the leech tale is flying since a narrow grove is all you will need and you will be able to sail as high (or fast) as possible with the breeze you have.
Posted By: davefarmer

Re: Slow in light wind - 07/15/14 01:16 AM

Nice reply Mike, thanks!
Posted By: davefarmer

Re: Slow in light wind - 07/15/14 01:16 AM

Nice reply Mike, thanks!
Posted By: Anonymous

Re: Slow in light wind - 07/15/14 03:15 AM

Don't let your rotation out upwind. Going upwind in light wind is all about efficiency. Read the first part of this this and set your mast so that it is working properly. Letting out the rotation is just adding drag. With a modern wing mast, rotation is the last place you should look (after cunningham and traveller etc) to changing power it should always be set so the luff tell tails are working. Once moving in really light wind your apparent wind will be a long way forward so if anything you need less rotation not more. Also don't be afraid to actively adjust this setting in the light. When you come out of a tack and have all but stopped the apparent wind will be at or above 45 degrees, as the boat accelerates it will swing forward to around 20-25 degrees so your mast setting will need to be changed to suit.
Posted By: Mpls_Nacra

Re: Slow in light wind - 07/15/14 03:18 PM

Thanks for the info, I cant wait to try it out. I'll let you know.
Posted By: US5352

Re: Slow in light wind - 07/15/14 03:43 PM

Hi Dave. Best way to get faster is to race with faster people who will share all their "secrets." Come to the CRAW regatta in Green Bay in three weeks, and you'll learn a bunch and leave faster than when you came.

Best,

Daniel
Viper F16
Posted By: Karl_Brogger

Re: Slow in light wind - 07/16/14 03:11 AM

Dave, if you want to come I'll even haul your boat for you.
Posted By: Mpls_Nacra

Re: Slow in light wind - 07/16/14 03:31 PM

Karl, I am planning on going to broken rudder. possibly one other event.

are you coming out to MYC again any time soon?
Posted By: Mpls_Nacra

Re: Slow in light wind - 07/16/14 03:31 PM

Karl, I am planning on going to broken rudder. possibly one other event.

are you coming out to MYC again any time soon?
Posted By: Rolf_Nilsen

Re: Slow in light wind - 07/16/14 03:46 PM

We also find that having quite some downhaul on in light winds is fast when being sucked upwinds. Usually there is not enough energy in the wind for it to stay attached over a Sail with a lot of draft. Flattening the sail removes the drag and perfomance loss of not utilizing all available energy in the wind.

I positively hate typing on a pad! And the norwegian spell checker does not help..
Posted By: rehmbo

Re: Slow in light wind - 07/16/14 05:52 PM

Read some place this mode (flat sail in light air) is akin to the aerodynamics of butterfly flight.
Posted By: Karl_Brogger

Re: Slow in light wind - 07/17/14 03:22 AM

It's usually so it opens the leech. Otherwise it's hooking severely at the top. You really aren't flattening it much because mast rotation will remain the same, and you aren't sheeting very hard.

I'll probably be up there at some point, no plans to store my boat up there this summer though
Posted By: Rolf_Nilsen

Re: Slow in light wind - 07/17/14 10:40 AM

A beachcat mainsail have about 10% draft when designed and built.
A rotating mast adds from 2-4% depending on mast.
Pulling on the downhaul will in my experience bend the mast and effectively flatten the sail.
After flattening with downhaul the leech can be sheeted in some more for additionally improved vmg.

A loose leech is the monohull way to reduce draft in low wind conditions ;-)

Try the different proposals and see what works for you.
Posted By: Mpls_Nacra

Re: Slow in light wind - 07/18/14 04:33 PM

Thanks again everyone, What about diamond wires. where should the tension be light, medium and heavy wind. ( I am on the heaver side of the scale)

thx
DF
Posted By: Karl_Brogger

Re: Slow in light wind - 07/18/14 08:47 PM

I adjust the diamonds a lot of times between races. If I feel under powered I loosen them, if I was maxing out the downhaul a lot I'll add tension.
Posted By: Rolf_Nilsen

Re: Slow in light wind - 07/20/14 08:32 AM

Why did sailors start experimenting with spreader rake and diamond wire tension..
They wished for a rig that was faster by automatically responding to small changes in windspeed. Depower in gusts and polering up in the lulls without the crew needing to do anything.
Spreader rake and diamond tension in the base form shapes the start setting for the mainsail. Draft and leech shape.



With a new Nacra i believe the supplied assembly manual specifies spreader rake and diamond tension to match the sails? I dont know the number but surely they are available online?
Beboere experimenting with spreader rake and diamond tension different then the factory /sailmaker spec, quite some time in the boat or a very broad beachcat experience is a prerequisite for good results in my opinion. This is a very fine grained tuning tool compared to sailing the right lane, boat balanse, helming, sheeting, starting, downhaul, roundings etc. I would run with the factory spec until I had the rest of the skills well done. On our current Nacra F18 that is exactly what we do. The settings are not what slows us down. It is our own boathandling and on the water decisions.
Posted By: waterbug_wpb

Re: Slow in light wind - 07/21/14 02:02 PM

Originally Posted by Mpls_Nacra
I find that when racing in light wind I am extremely slow.


When you say "Light Wind", can you give a range (windspeed or Beaufort)?

If memory serves, there was some discussion about laminar vs. turbulent flow breaking at about 8mph and the difference in AWA between surface and top of mast.

Sail settings and efficiency changed based on those parameters
Posted By: Mpls_Nacra

Re: Slow in light wind - 07/23/14 06:05 PM

Jay, I would say 7 mph and under.

thx
DF
Posted By: waterbug_wpb

Re: Slow in light wind - 07/23/14 07:09 PM

then you're overtrimmed smile
Posted By: Mpls_Nacra

Re: Slow in light wind - 07/29/14 04:55 PM

Hello all, I have had a chance to try a few of the suggestions out. I think I was a bit faster, but am still very slow. I think I need to keep getting out there an working on it.

Thanks for the input.
Posted By: Timbo

Re: Slow in light wind - 07/29/14 05:48 PM

Where are you putting your weight on the boat? In light air, I get as far forward as possible, to keep the sterns from dragging.

And DON'T PINCH!

And keep the jib flowing, open the slot between the jib leach and backside of the main, so you're not choking off the flow over the backside of the main.
Posted By: Mpls_Nacra

Re: Slow in light wind - 07/30/14 04:49 PM

Timbo, thanks.... I thought when sailing solo, one was not supposed to use the jib. So that is what I have been doing. Can I add it with out taking much of a hit?

thx
DF
Posted By: Timbo

Re: Slow in light wind - 07/30/14 05:47 PM

Well...per class rules, you are not supposed to use the jib if you are racing Uni. I use it all the time when I'm out on my lake alone, just practicing, but sailing in light air without it really, really, sucks! You miss it more there than at any other time, no doubt.
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