The 4th Dimension - Downwind Sailing

by Steve Cockerill, Rooster Sailing

Principally the 4th dimension is sailing by the lee with a single-handed boat that allows the boom to go out to nearly 90degrees. Steve learned the art of the 4th dimension sailing the International Europe internationally during the late 80's and early 90's and developed this skill later in the Laser during the 96 Olympic campaign.

Steve Cockerill tries to answer some of the common questions and explains the principles behind sailing by the lee, an area of sailing he likes to call the 4th dimension.

Sailing by the lee can be as stable or unstable as you want it to be. Try it for yourself

Some of the commonest questions asked at Training Talks are:
· What is the point of sailing by the lee?
· Why does it work?
· How do I start?

What's also amazing is that so few people have experienced the benefits of the 4th dimension yet it is not so difficult to learn with a little belief. Many top sailors from backgrounds in conventionally stayed boats can believe the concept but find it hard to change the habits of a lifetime.
Have any of you experienced sailing a laser dead running in lots of breeze, rolling heavily from side to side, sitting on the tiller praying to God that you are not going to capsize to leeward or to windward? Well this article's for you!

The Classic Approach to Wobbly Runs:
The classic advice is to use more kicker. This stops the leach from pushing you to windward because the leach will not be in front of the mast. More kicker will power the sail up in certain circumstances, and can be ideal for flat water sailing when broad reaching. However, it tends to flatten the sail excessively, reduce flow over the sail when dead running and make manoeuvring difficult. With excessive kicker, the power in the sail is held at the leach, which is along way from the mast. When manoeuvring from dead running, the centre of effort of the sail quickly moves from the centre of the sail to the leach and causes excessive amounts of weather helm and heel. Downwind sailing in waves is an art of wave avoidance rather than power sailing, so this unforgiving method of leach control will prevent you from avoiding waves. Typically, when luffing to avoid a large wave the leach will power up very quickly, tipping the boat and causing the boom to catch a wave top and you are swimming. Alternatively, if you don't avoid the wave you will nosedive and fall in anyway.

So to counter the classic advice I would suggest that there is another way to control the leach of the sail that does not flatten it, will stop the boat from rolling excessively to windward and makes it easier to manoeuvre. This is not an easy subject so I have split it down into understandable chunks……hopefully.

By the lee Sailing Development
The practice of sailing by the lee has been used in many single-handed classes. I like to think that I saw it practised best in the International Europe Fleet during the 80's. This was because the boom was so close to the water when sailing downwind with lots of kicker, that sailors developed ways of sailing with little or no kicker.







 A principle exponent of the 4th dimension was a Finnish Europe Sailor who was a student of the Finnish Sailing School (working hard during the winter to sail during the summer). All students had to devise a project and Yyurki Tarmanins was to investigate how little kicker he could use downwind without opening the leach. He turned up to an International Easter regatta in Holland in 1985 with what seemed like 100 pairs of tell tails on his sail. I remember at the time that he sailed with far less kicker than everyone else, and yet his leach still looked remarkably closed. Two years later I learned of his findings first hand when we trained in France in preparation for the Europe World Championships.

Let's go through some of the benefits:
1. Avoid those wobbly runs
2. You can sail with a fuller sail
3. Use the rudder as a life saver
4. Wave Avoidance made Simpler
5. Transitions the Key to Success
6. Remain in tactical control on the run

Avoid those wobbly runs
I have seen so many sailors struggling on a run in a laser, in fact I remember doing it myself as a youngster. I remember wondering which side of the tiller should I be sitting on and ending up sitting on it and praying, soon to be accompanied by a loud splash! Sailing dead downwind is a bit like watching a flag fluttering in the breeze. The wind flow moves it one way and then the other. In a similar way if you sail dead downwind, the flow over the sail alternates from leach to luff and luff to leach making the boat almost impossible to control. Try the 'by the lee' way and you will find safety in the confidence that the boat will behave consistently. This video clip shows the new reaction you should have to the boat heeling to windward - 295KB You will need the Windows Media Player. Right mouse click to save to disk for playback at your leisure.

Sail with a fuller sail

When sailing by the lee, the wind flow is from the leach to the luff of the sail rather than from luff to leach. Hence little kicker is required, as the mast is the hardest leach anyone could want. The sail can be sheeted in until the leach starts to flick, thus increasing the wind flow over the sail and reduce the load on the leach. Please note, if the kicker is on too much, there is very little room for error before the boom gybes

Use the rudder as a 'life saver' checkout this clip (click to download video 508KB) - KB You will need the Windows Media Player. Right mouse click to save to disk for playback at your leisure.













The common running problem is the violent roll to windward that causes the boat to start to bear away radically. What do you do? Perhaps you pull the sheet in and move your weight to correct the trim, but lets concentrate on the rudder. Do you push the rudder away from you (head up) or pull it toward you (bear away)? For most of you it is probably inconceivable to pull it towards you, but that is actually the right answer! You see the alternative is to push it away from you. Then the angle of the rudder will act as a lifting plane and lift the transom out of the water and accentuating the roll. If you pull it towards you, the rudder becomes a lowering plane and drives the boat both deeper 'by the lee' and forces the boat upright. At the same time, the rig once again becomes stable as the power on the leach is removed (more flow, less push) and the boat again becomes stable.

This caption look familiar?

Wave Avoidance made Simpler:
Downwind sailing can be likened to running through a badly organised car park. There always seems to be a car in the direction you want to run in and it is always a compromise direction you take. Occasionally there seems to be a gap opening up which takes you where you want to go at speed, but invariably it's a question of zigzagging through the parked cars. Well the same is true of sailing downwind in waves. If you want to spend your time climbing over cars, then sail straight downwind! If you attempt to avoid waves but cannot do the 'by the lee' thing, then the only option is to head up when facing a wave front (parked car) which must limit the possibilities of making the fastest progress downwind.

Transitions the Key to success Download 1.5M - checkout the quick easy turns on flat water (click to download video 1.5MB) You will need the Windows Media Player. Right mouse click to save to disk for playback at your leisure.

The transitions between normal and 'by the lee' sailing are a crucial tool in the Downwind toolkit when sailing in waves, or car avoidance if you are still thinking of cars in a car park. Each transition needs to be both smooth and give acceleration, in a similar way to roll tacking upwind.

To bear away: (click to download video 400KB) You will need the Windows Media Player. Right mouse click to save to disk for playback at your leisure.

the helm must ease the mainsheet, creating a roll to windward (due to the leach powering up and moving forward). This would normally result in a capsize to windward if no further action were taken.
bear away hard with the rudder, flattening out the boat (using the rudder as a life saver discussed before) and reducing the angle of the sail to the wind (effectively sheeting in) and you are there safe and sound!

To head back up again: (click to download video 380 KB) You will need the Windows Media Player. Right mouse click to save to disk for playback at your leisure.

the helm must induce the transition by pushing the boat to leeward (conventionally minded) which also induces a pump to windward (which turns the boat away from the wind)
at the same time sheeting in getting ready for the new force on the sail from the wind in the conventional direction
and sitting out against this new force and the centripetal force of the turning hull.

N.B. Make sure you have sheeted a lot in before you sit out as you might find it go very dark and wet. See the clip above and notice how much sheet is pulled in to finish off the transition up.

This is what is should look like when you have got it right (click to download video1.5MB) You will need the Windows Media Player. Right mouse click to save to disk for playback at your leisure.

Remain in tactical control on the run
Simply the lower you can go at the top mark on the run, the greater the chance of getting the inside overlap at the Leeward Mark. The bear away at the mark is the first crucial aspect to this which is really just the bear away transition discussed above. Clearly there is a lot more sheet easing, but it is this aspect that is the most crucial to begin the transition, then use the rudder as the 'life saver' to end the transition. Once you are sailing deep and 'by the lee', the rulebook becomes your friend. If anyone attacks you to windward (conventionally speaking), you have the option to luff hard or go lower. The lower option might be preferred, as they cannot be on your wind as you are sailing 'by the lee'. Don't forget, whilst sailing by the lee, the boom still dictates the gybe you are on - if the boom is over the port side of the boat you are still on starboard. So being on starboard 'by the lee' makes it interesting when approaching a boat on port sailing the same course! Putting yourself in this deeper passing lane gives you an easier route to the mark and makes for simpler mark rounding strategies. Faster boats that are not as deep as you must not only gain an overlap but must also pass you to break the overlap to stop you maintaining your place at the leeward mark. This strategy works well when sailing a typical left handed course that has been set true to the wind and tide.

How do I start?
Now you have got all the facts, it might be worth going over them in your mind one or two times, but trying is really the only way to start. Be prepared to get wet, the more committed you are, the more chance you have of getting wet and learning quicker. I suggest you wear a warm wetsuit! Try these exercises as a starter.


Trying it For Yourself
Remember things are back to front, so de powering the rig is sheeting the sail in and bearing away will feather the boat in a gust.
Start by sailing in light winds on flat water and practice the transitions from broad reaching to by the lee. When there, try more and less mainsheet and feel the differences on the boat. Try to sail as far by the lee as possible. Reaching on the opposite gybe is possible. When the boat heals in a gust just sheet in a bit more (effectively easing the sail) and bear away even more, until the leach recovers and then you can resume the less radical bye the lee course. I understand the concept of using the rudder as a lifesaver is difficult to grasp. Start by sailing downwind with the rig over you and see what steering the rudder from side to side does. You should notice the effect of it making the boat roll over more or less as you do so. Try steering the rudder with the tiller extension on the leeward (conventionally speaking) deck, it might help you feel in more control. You can make by the lee sailing as stable or unstable as you like, it just depends on how much weight, rudder and sheet movements you are prepared to make.



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