Sail Trim In Light Air

[Ducati]

I spent the day bobbing in light air trying to trim sails for winds under 1 kt. The windex also couldn't make up it's mind so that added to the fun too.

Looking for suggestions for trimming sails (when racing) upwind + downwind (non-spinnaker) in super light air.

Thanks

 

[Ken13559]

jump in the water and clear those barnacles and weeds.

 

[Stu Jackson]

Light, light sheets.

 

[DougM]

Park the boat and go play golf...(?)

 

[RedRex]

light air

Spinning windex is no air. With a name like ducati don't you have a motorbike? Or should you put on your olive and yellow checkered slacks and play golph?

Know when to give it a rest,
Red

 

[Joe Diver]

You need the right sail. Unless you have a specialized giant drifter, forget it.

I saw an ad for one...big 150 or 165, can't remember which...but it was so thin and light you could see the person standing on deck through it. That thing would catch a fart.

Even if you do get some wind and motion, don't expect much at all, like a knot or two...barely enough for steerage.

 

[Ted]

You need light weight sails. The headsail must be small, something like a 100% LP because if you use a large overlapping genoa, the air will have a difficult time of staying attached. Keep crew weight to leeward to have gravity help add some shape to the sails. One knot of wind speed is not going to make anyone very happy even with the right sail inventory.

 

[Rick D]

Light Air

Most of the races I have won (or more often placed) are in light air. First, you need a jib pole of some type. Second, a clean bottom. Third, a vang/preventer rig for the mainsail. Fourth, a folding or feathering prop. Fifth, an attentive crew.

I did replace my factory sails some seven years ago and got about an ounce lighter in both. I also did not have a heavy Sunbrella-type protective cover for the jib and instead went for a sacraficial dacron cover good for a couple of years. It allows the sail to fly much easier in light conditions. I bought a sock to put over the jib when I'm away to protect the sail. Also, for light air, unless you have a true drifter, a big overlap (150+) isn't necessarily the best way to go. I fly a 133 on a fractional rig.

As far as sailing tactics in light air, you probably already know them. However, I do not pay attention to the wind indicator under a couple of knots apparent. I am typically in swells and the masthead fly gets tossed all around. Trust the back of your neck instead and sail to the best 'average' course. Don't even try DDW; just get the wind over your quarter or beam to steady the sails and get some apparent wind moving.

As far as an attentive crew... good luck getting them to pay attention after sundown when they are tired, cold, and just want it to end.

Anyhow, that's what I do and it seems to work, but every boat and crew are different, so doing a bunch of races is the best solution to moving up the finish list. Good luck!

 

[Gudenuph]

My take on this is to pay particular attention to the top of the sails as that is where the wind is. Also the wind flow will be laminar and twisted to the right with height above the water as well as having increased speed. Use the topping lift if necessary to allow the main to twist when on starboard tack and the vang (or less topping lift) when on port. Follow suit with the jib trim. Heel the boat to leeward and move about very gently or not at all.

FWIW, Geohan

 

[higgs]

Don't let crew move around, keep them leeward.

 

[RichH]

There is only one way .... FLAT sails and get the boat moving, in any direction possible .... and then when you build boat speed ,your apparent wind will increase & you can adjust/increase the amount of draft to keep the flow on the leeside of the sails attached (by very carefully watching the tell tales).
If you have 'recreational cut' sails (rounded luff shape), you will have to slack the halyards so that you can remove as much 'roundeness' to the 'luff entry' section as possible ... but then the crew will have to move their weight well forward to help counter the 'weather helm' that will develop because the point of maximum draft will go aft in a luff-slacked sail ... so dont 'overdo' the halyard loosening.

To accelerate you WILL have to bear off, a boat with sails this flat simply wont get moving, you must 'rap-off' with eased main/jib sheets.

In this condition you will need to CLOSE the slot distance ... the leech of the jib will have to be moved closer to the mainsail ... typically by barberhauler. Once you get 'some' speed going and with the sails leeches parallel to the boats centerline ... then start barberhauling in while watching the speedo for MAXIMUM vs. the amount of barberhauler needed .... dont overdo the barberhauling as this will 'choke' the slot. When barberhauling totally ignore any 'backwinding' ... watch the speedo.

FLAT sails so that the flow stays 'attached' to the sails.
Get the boat 'moving' to increase apparent wind
No sudden crew movements.
Never take a motorboat wake dead on the bow ... bear off even to a beam reach if need, then 'come back' up.

Down wind .... same story, *keep the speed up* even if its sometimes below a beam reach ..... 'tack down wind', even with a spinnaker flying.
Stay 'under' any clouds (summertime) .... watch the windshadows developing on the water and dont fall into a 'hole'.
Favor being close to any shore .... for shoreline 'seabreezes' from any difference between land and water temps.

Once you get moving and with competitors 'behind', .... shoot turbulence at your competitors by occasionally s-l-o-w-l-y pulling in hard on the main to 'hook up' the leech on the main .... may cause any aft boat to 'fall into a hole' (sending them your 'vortex' ... will be a 'header' for a following boat for 4-5 boatlengths back on the same tack) in the wind from which they cant accelerate out of. Dont kill your boatspeed in doing so.


FLAT sails, drop the traveller to accelerate, do 'anything' to keep boatspeed up to gain apparent wind. You may need to use the topping lift if your boom is too heavy, etc.

;-)

 

[Ducati]

Thanks everyone for the great info...even you too Red.

In my opinion races are won or lost in light air and we mostly focus on trim when sailing conditions are good. Light winds are a real pig to sail in and the only good thing is that crew get to sip beer when things go flat.

 

[higgs]

Flat sails? I always thoguht one wanted to ease the main outhaul to add a little curve to the foot. I have always flattenened sails in heavy air. Have I been wrong?

 

[RichH]

Flatness according to the mid cord leeside tell tales. Too much draft and the tell tales will 'tell' you when a separation stall begins. Use tales made from wrinkled old micro-cassettes for racing in the 'very light' winds.

What youre watching for is invisible 'separation stalls' ... not enough energy in very light winds to keep the flow 'attached' .... to rounded or too much draft and the flow 'easily' separates.

Yes, initially set up you basic sail shaping for 15-18 kts. with full up sails when sailing in less than 5kts., then adjust for max. amount of draft via outhaul while watching the leeside midcord, etc. tales ... and of course the speedo. ..... just remember that in light winds any sail shape adjustment takes time for the boat to build speed, ... so dont get 'antsy' when you make any shape adjustment.

If you have a 'bendy mast', apply LOTS of backstay tension (like you do when 18+kts) to flatten the main, while watching the tell tales AND speedo very carefully .... +/- outhaul and/or fairlead car position.

;-)

 

[mark_swart]

Sometimes when the air is so light the telltale is spinning, you can light a cigarette/cigar to see a very faint wind. I don't smoke, but I can think of two occasions where we have won races due in part to my dad lighting a cigarette when the wind fizzed. Haha, I guess incense would work too if you are as grossed out by smoke as I am.

A length of tape from an old-school cassette tied onto the shrouds also moves in very light air.

Don't move around any more than you have to and keep the sails in the position they need to be in by using preventers or poles. If a tiny wisp of wind comes, that way the force will go towards your momentum instead of just pushing your sails into shape.

You have a big boat, but putting crew on the 'low side' to get the sails into shape also can help. This applies both up an downwind.

Light air racing is the most tedious thing in the world.

 

[Jumpstart]

Light air/drifter. Attaching flow is key. Twist is your friend. Upwind, traveler, ease mainsheet- lots of twist. As apparent increases traveler down and tighten mainsheet gradually. Genoa - cars aft, ease sheet at least a foot to a foot-1/2 off spreaders. Crew weight forward but behind the shrouds and to leeward. If it's lumpy put the "dogs in the house" sitting on the cabin sole near the mast.

 

[Joe]

Let me jump in here at the end to comment further on crew position... that would be to move the ballast forward, with the goal of getting the stern up out of the water.... at least move everyone out of the cockpit except the driver... the headsail trimmer can stand on the windward rail, just behind the shrouds with the speedo still visible, cross sheeting on a cabin top winch... the other crew can sit around the mast.... all are looking for wind... the idea is to get the ass end of the boat up out of the water to minimize rudder drag.