You are here: > technical > technical manual > light winds

Technical Manual

When The Going Gets Light, The Light Get Going

by Geoff Woollen

It always happens - the groans from the heavyweights. "Not another drifter". "Another race for the fairies to win !". However, whatever your own weight unless you've developed some light weather speed you could find your name slipping down the results list rather frequently. Many championships and open meetings, and more often inland events, feature some 'light stuff'.

"But there's no action!" Whilst admittedly there may not be the adrenalin-stimulating wave jumping etc. light weather sailing need not be boring. Indeed with the physical fitness differences no longer significant it could be argued the helms persons skills are more important.

The fact is that the race is conducted more slowly. The lack of planing, and manoeuvring disturbances of other boats tend to keep the fleet closer together giving less opportunities to get clear. This makes it all the more important to make the right decisions since mistakes, for example about which course to take, can cost you dearly.

It is important to consider the OK rig itself and the restrictions its design imposes. Most of us have only one sail which generally represents something of a compromise. It should be giving us something like full power when sitting out hard in a Force 3-4 without Cunningham. In wind strengths above this we depower by sheeting harder and pulling on the Cunningham to open the leech and spill wind. This type of rig therefore tends to be rather full when set up with only slight mast bend. A full sail is unsuitable for light conditions, since the air flow is unable to follow the pronounced camber and speed sapping turbulence results. The leech also will have a marked tendency to hook up to windward, again inducing drag. Therefore it is necessary to sheet in the sail to bend the mast, and so take the fullness out. Don't overdo it though by attempting to close the gap between boom and deck as excessive creasing will result in the sail luff. We do not want to use the Cunningham to correct this as this will pull too much camber forward giving a poor angle of attack. The objective is to give the sail a smooth even camber with the maximum draft about 45% back. The traveller should be set inboard some 6" or so, so that the leech does not hook to windward. Certainly this would be the case if the traveller was sheeted to the centreline - leave that technique for two sailed boats.

The result will be a rigid 'flattened' sail with a taut leech which will move little in up to Force 2-3 winds. In very light winds at sea the tight leech itself can be a problem since wave-induced movements can literally knock the wind off the sail. Under these conditions it may be desirable to free off considerably and allow the leech some freedom of movement. Inland it may be desirable to point slightly higher at the expense of speed, but at sea where there are often waves even in light winds these would result in stopping the boat. Better to sail slightly lower and maintain maximum drive.

Upwind the boat will be sailed with a slight heel to lift the windward chine out of the water thereby reducing wetted area, and also to help the sail to fill. Your weight should be kept well forward upwind and downwind to keep transom water disturbance to a minimum. Offwind on broad reaches and runs the boat is heeled to windward and the boom held out by the elastic strap. The 'centre of effort' of the sail should be directly above the boat so that a neutral balance on the helm is achieved. The objective is to avoid having to make rudder corrections as these will slow the boat proportionally more than usual. You should aim to steer the boat by balance although I must admit its sometimes easier said than done.

Roll tacking and gybing are skills acquired by observing others and then continually practising. The technique is not one of speed, rather that it should be done smoothly to ensure minimum disturbance from sudden sail or hull movements, yet maximise the benefit from induced wind in the sail. Whilst the rules forbid tacking and gybing specifically to induce artificial motion you should ensure you are doing it no less than those round about. Often a pair of boats in a tacking duel will find themselves motoring through the fleet - perhaps that's why they were doing it. Otherwise let the small windshifts give you the reason to tack as necessary.

The physical inactivity also should not encourage mental drowsiness, since concentration as always will produce results. It could be that minute but significant extra speed can be coaxed out of the boat by minor experimentation with sail trim, so don't be afraid to try. Careful observation of wind variations on other parts of the course can give early signs. Also watch your opponents' technique - it might give vital clues about the fastest way to sail the boat in a particular set of conditions.

With regard to the boat itself if you are convinced your boat is fast it will give you the confidence so that you really can be as quick as anyone else. A good smooth underwater finish is essential - don't forget the foils. Attention to detail off the water will allow you to spend more time thinking about the sailing on the water. Do all your controls run smoothly and friction free so that you don't have to shift your weight around to help them work without the wind forces? Do you have to jump on the centreboard to get it up, or push the boom out when you go on a run? These things may be small but disturb the delicate balance that gives maximum forward speed, and of course they divert your attention.

Tactics also are important especially when protecting your 'right' to free air. Disturbed wind flow from upwind boats will result in lost places far quicker in these conditions. Aim to start in clear air even it means sacrificing a few yards to do so.

This article may not have given you all the answers to light weather OK sailing. However, hopefully it will at least have persuaded you it is not necessarily the lightweights who win in light weather, but the best sailors!