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Light Wind

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Post Options Post Options   Quote FreshScum Quote  Post ReplyReply Direct Link To This Post Topic: Light Wind
    Posted: 12 Oct 08 at 9:59am
A mode changes should occur when the wind flow switches from being laminar to turbulent. This happens at around 4knots depending on other factors such as humidity, air density, pressure etc. The sail shapes required for these two separate conditions are very different.
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RyanV49er View Drop Down
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Post Options Post Options   Quote RyanV49er Quote  Post ReplyReply Direct Link To This Post Posted: 12 Oct 08 at 9:52am
That's how I started out, on inland lakes.  But you can't really learn anything if the breeze is always light so I've had to get to southampton (from oxford) every weekend for the last 6 years..  I'd hate to think how many miles I've racked up doing that every weekend.
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Post Options Post Options   Quote Lukepiewalker Quote  Post ReplyReply Direct Link To This Post Posted: 12 Oct 08 at 5:06am
Clearly not a small pond sailor then. Most of my sailing career has been in less than 5 knots.
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Post Options Post Options   Quote redback Quote  Post ReplyReply Direct Link To This Post Posted: 11 Oct 08 at 11:15pm
And at 3 knots its enough wind to power up the rig with full sails.  Incidentally if its less than 5 knots you should be in the bar.
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Post Options Post Options   Quote RyanV49er Quote  Post ReplyReply Direct Link To This Post Posted: 06 Oct 08 at 5:43pm
Sailing heeled only works in very light winds.  After about 3 knots it starts making you drift sideways, so when you get the power in the sails to keep them filling when flat, keep her upright, bow down, don't hook the leech, open the slot and get your crews head out of the boat to find those gusts.
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Post Options Post Options   Quote JonnyW Quote  Post ReplyReply Direct Link To This Post Posted: 03 Oct 08 at 8:17pm
Sailing a Merlin
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Post Options Post Options   Quote G.R.F. Quote  Post ReplyReply Direct Link To This Post Posted: 29 Sep 08 at 9:33pm
The trick in light airs, which I've also found true on dinghies, is to heel the
boat to leeward just enough to ensure gravity assists the sails natural curve,
this also, depending on the particular boat hull and rocker, may naturally
point the boat to weather, but this should be avoided, it is often better
particularly in drifters, to keep moving by sailing a tad freerer to ensure a
ready supply of created wind to make up for the lack of true wind in the
lulls.

Rigging the sail with not too full a draft, certainly not to tight or hooked a
leech and as fine an entry as possible will all contribute positively as will
keeping a weather eye open on the water as to where the damn wind is
anyway

Edited by G.R.F.
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Post Options Post Options   Quote jeffers Quote  Post ReplyReply Direct Link To This Post Posted: 29 Sep 08 at 6:43pm
Originally posted by KennyR

Depends on the boat.



Exactly....let us know what class you are sailing and better targetted advice will be forthcoming.

I have sailed a variety of classes and they all vary. The Laser for isntance needs a little bit when it is light, the Blaze you just didn't use the kicker until you were stupidly over powered. The 8.1 you need a fair bit at all times to match the mast to the luff curve.

The other (perhaps more important control) in the light is the Outhaul. A lot of people think the lighter it is the less you should use. Not so! In light winds you need to make the path for the flow as easy as possible to prevent it from becoming detached from the sail (not fast or efficient).

In medium airs when are are searching for power you want to loosen the outhaul off so the wind is deflected the maximum amount (this helps generate power) whilst keep the flow attached.

In heavy airs you want to reduce the power so it is back to tightening up the outhaul to help depower the sail (in conjunction with judicious ammounts of cunninham to open the top or 4th corner which is somewhere near the top batten on most sails).

It is all about phyiscs, take a little time to understand what is happening to the air as it flows over the sail (you do not need to be an aerodynamicist) and the whole idea of what you need to do becomes a lot clearer and easier to understand. Putting that all in to practice however it an entirely different matter and takes time on the water and help from more experienced people/instructors.

Just my 2p as always, i am sure someone will explode my outhaul reasonings somewhere along the lines!

Paul
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Post Options Post Options   Quote KennyR Quote  Post ReplyReply Direct Link To This Post Posted: 26 Sep 08 at 2:51pm
Depends on the boat.

Two sails. Tight outhaul almost all the time, maybe off
an inch or so in the lumpy stuff if you are
underpowered. Ease it any more with the boom on the
centerline and the leech points up to windward and acts
as an air brake. Not fast. Easing it a bit gives more
weather helm to give the rudder lift and some feel, but
be carefull.
One sail is completely different. To start with the sail
needs to be thought of as a jib and not a mainsail.
Hence the basic shape is different because of that with
the draft much further aft than on a two-sail boat's
mainsail. Therefore you need to sheet down 10degrees or
so from the centerline i.e boom end over quarter roughly
- Look at the way a laser or finn sails upwind. This
means the outhaul can be eased a lot more before the
leech hooks up to windward as it has to 'hook' by 10
degrees or so just to reach parallell with the
centerline of the boat. In some cases this ease will be
several inches with quite a 'bag' in the lower half of
the sail. Whilst sail cut also has an effect, you can
usefully use a lot more outhaul off on a singlehander.
Quite common in Finns to use the outhaul as the primary
'power' control once the boomis on the deck.
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Post Options Post Options   Quote JonnyW Quote  Post ReplyReply Direct Link To This Post Posted: 26 Sep 08 at 2:31pm
thanks all will try the suggestions
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