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Kit Guide

Top Reads 2016 #3rdplace - Explaining the 4th Dimension

By Steve Cockerill 2nd October 2020

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

I hope to answer some of the common questions and to explain the principles behind 'sailing by the lee', an area of sailing I termed the 4th dimension.

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

What is 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. 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 leeward and makes it easier to manoeuvre. This is not an easy subject so I have split it down into understandable chunks……hopefully.

Steve's Postulates or Laws: They will become vital tools in your understanding. 1st Law - pull the rudder towards you and the boom goes towards the water. 2nd law - push the rudder away from you and the boom goes away from the water. 3rd law - nothing else is always true.

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, so the sailors had to develop methods of sailing downwind 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 Tarmanin's 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: Avoid those wobbly runs You can sail with a fuller sail Use the rudder as a life saver Wave Avoidance made Simpler Transitions the Key to Success 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 would wonder 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. Once you start trying to sail the boat under the rig, you are in danger of obeying the 1st or 2nd law - and the boat starts to wobble. Also 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' or '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.

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. This means that 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’(1st law) 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! This obeys my first law. Pull the rudder towards you and the boom goes towards the water. 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 accentuate the roll (the 2nd law). 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 is explained best visibly the Boat Whisperer Downwind DVD, with some great video and some demonstrations with with my radio controlled laser.

Boat Whisperer DVD Downwind Steve explains how the rudder effects heel on the Downwind Boat Whisperer DVD

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 ultimately limits the possibilities of making the fastest progress downwind.

Transitions the Key to success 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 (from a reach): the helm must ease the mainsheet, creating a roll to windward as the load is reduced. 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 (1st law) as discussed before and reducing the angle of the sail to the wind (effectively sheeting in) and you are there safe and sound! There are some other movements that are required at this stage with moving the body to leeward - again best shown and described on the Boat Whisperer Downwind DVD.

Screen Shot 2016-01-20 at 14.49.34 To head back up again (from By the Lee): So whist By the Lee, the helm must induce the transition (back to the reach) by pushing the boat to the new expected leeward (towards the boom). This is however, currently the windward side of the boat so it will induces a pump to windward (which turns the boat from By the Lee, through the dead run to a reach). I tend to do this in a Laser by standing up to leeward and inducing a push with my legs. Screen Shot 2016-01-20 at 15.16.41 Screen Shot 2016-01-20 at 15.16.51

Then as you turn, you must at the same time keep sheeting in as the boat makes the transition so it will not death roll to windward once you have finished the turn. (this is because the turn will generate a heeling effect from the mast's centripetal force which finally finishes once the turn has completed.

Screen Shot 2016-01-20 at 15.16.34 Now the sail is in, you can happily sit out against this new force as the centripetal force of the turning hull diminishes. N.B. Make sure you have sheeted a lot in before you transfer your weight as your weight could kill the turn.

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 you are still on the gybe the boom is on, 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 warm tested sailing equipment! Try these exercises as a starter.

Screen Shot 2016-01-20 at 14.49.34

Trying it For Yourself Remember things are back to front when you are 'By the Lee', so de powering the rig is sheeting the sail in and bearing away will feather the boat in a gust. Confused??? Start by sailing in light winds on flat water and practice the transitions from broad reaching to 'by the lee'. Once 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 with a gust, just sheet in a bit more (effectively easing the sail) and bear away even more (effectively fethering the boat). The gust acts in two ways. It obviously give you more heeling moment die to increased wind strength. It also blows the leach forward as it is less supported which makes the boat think you have eased the sheet out (but the lee that's pulling it in). When you sheet in or bear away, you are relieving the load on the leach so it can recover and allow you to resume the less radical by 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.

Screen Shot 2016-01-20 at 15.41.01Try 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. Still confused, you might find the Boat Whisperer DVD's easier to follow.

Here is a short bit of downwind sailing at Cabarette where I am struggling to pass my very capable wife. The waves were rather uncomplicated but were worth a by the lee bear away at the point in the wave where you needed the most acceleration to take a fast ride.

Also as an extra bonus - there is a short burst of video taken in slightly windier conditions - same venue.

I can be regularly found racing in various circuits, so do stop me and ask me. Lastly - you might want to jack up a Boat Whisperer Talk at your club.

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