Oscillating or Persistent? Not Every Wind Shift Should Be Treated the Same Way

Learning to Race — From First Start to Better Results

Sometimes a header tells you to tack. Sometimes it tells you to stay exactly where you are.

You are sailing towards the windward mark when the wind changes direction. The sails begin to lift, you bear away to keep the boat moving, and suddenly your bow points further from the mark.

You have been headed.

The familiar advice springs to mind: “Tack on a header.”

Often, that is a useful response. But sometimes it sends you towards the wrong side of the course, just as the wind is making that side increasingly unattractive.

The next step in learning to race is understanding that a wind shift has more than a direction and a size. It also has a pattern.

Is the wind swinging backwards and forwards? Or is it progressively turning one way?

That distinction can change your whole plan for the beat.

First, Remember What a Header Actually Means

On an upwind leg, a lift allows you to sail a heading closer to the windward mark. A header forces you to sail a heading further away.

For two boats on opposite tacks, the same change in wind direction generally lifts one and heads the other.

In the previous article, Headers and Lifts — Turning Wind Shifts Into Distance, we explored why this matters: two boats can sail at similar speeds yet make very different progress.

Now we need to add another question:

What is likely to happen after this shift?

The answer determines whether you should take the immediate improvement offered by a tack, or accept a less attractive heading while positioning for what comes next.

Oscillating Wind: The Swing That Comes Back

An oscillating breeze shifts backwards and forwards around a broadly stable average direction.

Imagine these illustrative wind-direction readings, taken at regular intervals:

270 degrees → 280 degrees → 270 degrees → 260 degrees → 270 degrees.

The wind swings right, returns, swings left and returns again.

Real wind is less tidy. The shifts may vary in size and duration, and you cannot assume that they arrive on schedule. Nevertheless, repeated returns towards a similar direction suggest an oscillating pattern.

In these conditions, sailing the lifted tack is often productive. When the wind crosses to the other side of its average direction, changing tack can let you take advantage of the new phase.

A practical example

Suppose you have established a normal close-hauled heading on each tack before the start.

On starboard, you are now sailing noticeably worse than your normal heading. Meanwhile, port would offer a better heading than its own normal value.

Provided you have room, clear air and a worthwhile shift, tacking makes sense.

You are responding to a meaningful change relative to the average—not simply to the fact that your bow moved a little.

That distinction matters. A boat can lose some of a generous lift and still remain on the favourable tack.

“We have been headed” does not always mean “we are now on the headed tack.”

Persistent Wind: The Shift That Keeps Going

A persistent shift moves predominantly in one direction over the period that matters to your race.

An illustrative sequence might be:

250 degrees → 260 degrees → 270 degrees → 280 degrees.

Instead of returning towards its earlier direction, the wind keeps turning clockwise.

“Persistent” does not mean forever. It means that you expect the change to continue, or the new direction to remain, long enough to influence your route to the mark.

A shift that reverses after fifteen minutes may be effectively persistent during a five-minute beat.

Here the strategic priority changes. You generally want to position towards the side from which you expect the new wind direction to arrive.

For a continuing right shift, that usually means favouring the right side of the beat, looking upwind. For a continuing left shift, it usually means favouring the left.

Why Staying on a Header Can Be the Right Decision

This is the part that can initially feel backwards.

Imagine an open-water beat with the mark initially straight upwind. You have credible evidence that the wind will continue shifting right.

Port tack takes you towards the right side of the course. As the wind turns right, port is headed.

Tacking immediately onto starboard would give you a lift—but would also send you back towards the left.

If the rightward trend continues, a boat that has stayed further right can gain an advantage. When it eventually tacks onto starboard, the changed wind direction gives it a better approach towards the mark.

In the simplified case:

Expected continuing right shift: favour the right, often sailing port first.

Expected continuing left shift: favour the left, often sailing starboard first.

This is why “tack on every header” can fail. It can repeatedly pull you away from the side that the developing wind favours.

However, this is a positioning principle, not an instruction to sail indefinitely away from the mark. Your starting position, remaining distance, current, wind strength and the course boundaries still matter.

There is no prize for predicting the shift correctly and sailing beyond the useful turning point.

How Can You Tell Which Pattern You Have?

One shift is an event. Several observations begin to reveal a pattern.

Before the start, spend some time sailing close-hauled on both tacks. Notice your normal headings and the range of variation.

During the race, ask:

• Does the wind repeatedly return towards its earlier direction?

• Are successive highs and lows moving progressively one way?

• Are boats elsewhere experiencing the same change?

• Does the change happen in the same place on each lap?

• How long remains before we reach the mark?

A compass helps, but useful observations are possible without one. Compare your bow with distant landmarks while sailing properly close-hauled, and watch the headings of boats in clear air.

Keep comparisons consistent. A course over the ground shown by GPS is affected by current; it is not the same thing as the direction in which the bow points.

Also check that the apparent header is really a direction change. Dirty air, a lull, poor trim or a change in boat speed can alter what you feel through the sails.

Do not build an entire strategy around a boat that has simply slowed down.

River Racing Adds Another Possibility: The Wind Changes with Place

On the Thames, trees, buildings and the shape of the river complicate the picture.

Imagine that you sail towards a particular stretch of bank and experience a header. On the next lap, it happens again in almost the same place.

That may be a geographical wind change rather than a breeze progressively turning across the whole course.

The distinction is:

Has the wind changed while we have been sailing, or have we sailed into different wind?

On a river, both can happen together.

Consider an illustrative choice between two routes. The right offers the expected favourable shift, but lies beneath trees in noticeably weaker wind. The left has a less attractive angle but stronger pressure.

In light conditions, the stronger wind may outweigh the directional advantage.

Current can change the calculation again. When beating against the flow, quieter water near a bank may help—but only if there is enough breeze to keep the boat moving.

River racing rewards a combined judgement:

Wind angle, wind strength and current must be considered together.

The Breeze Can Oscillate While Its Average Moves

The wind does not always fit neatly into one category.

Consider:

250 degrees → 265 degrees → 255 degrees → 275 degrees → 265 degrees → 285 degrees.

There are reversals, but the overall trend is towards the right.

Here you may still use the smaller oscillations to choose your moments to tack, while gradually working towards the right side.

That requires more thought than either “always tack” or “always stay”.

It also means updating your reference headings. A number that represented a good lift ten minutes ago may no longer be favourable if the average direction has changed.

Your observations should update your plan, not merely decorate it.

What This Means Aboard Champagne

Aboard an A-Rater such as Champagne, I would make this part of the conversation between the crew.

There is a useful difference between:

“Header—tack!”

and:

“Header again. Is this another swing, or are we still working towards the right?”

The second call gives the helm information about the decision, rather than just the latest symptom.

A simple division of attention could help: one person watches boats and approaching pressure, another keeps track of headings and the mark, while the helm concentrates on sailing the boat efficiently.

For me, the appeal of racing is increasingly this combination of observation, discussion and judgement. Boat handling remains essential, but the more interesting question becomes why we are choosing a particular route.

A well-executed tack is valuable. A well-executed tack made for a poor reason can still lose ground.

Try This During Your Next Club Race

Choose one beat as an observation exercise.

Before the start, establish a rough normal heading on each tack. During the beat, identify a few meaningful shifts and say what you think is happening:

“Swinging back.”

“Still trending right.”

“Different wind by the trees.”

Afterwards, compare your expectation with the result.

Did the wind return? Did the trend continue? Did another boat gain because it found more pressure rather than a better angle?

Avoid judging the decision solely by where you finished. You can make a sensible decision that loses to an unexpected change, just as a poor decision can occasionally be rescued by luck.

The aim is to improve the evidence behind your next choice.

Near the Mark, Time Changes the Answer

Even a normally oscillating breeze may need a different response near the end of the beat.

If the wind usually swings back after several minutes, but you are only forty seconds from the mark, the next reversal may arrive too late to matter.

Reaching the mark efficiently now becomes more important than positioning for a future swing.

Similarly, a persistent-shift strategy must stop short of overstanding: sailing further than necessary because you failed to account for how the changing wind moved the layline.

Keep asking:

Will the change I am waiting for happen before it can still help me?

Conclusion: Read the Pattern Before Choosing the Response

“Tack on a header” remains useful advice. Understanding when to apply it makes it more useful.

An oscillating breeze often rewards taking the favourable tack as the wind swings. A persistent shift often rewards positioning towards the expected new direction, even when the first part of that route feels uncomfortable.

On the river, pressure, current and local wind bends add further layers to the decision.

You will not predict every shift. Nobody does. But you can replace an automatic response with a reasoned one.

The next time your sails lift and the bow falls away from the mark, ask:

“Is this wind coming back—or am I watching the course change?”

That is a significant step from learning to sail a race to learning how to think your way around one.

Follow Learning to Race — From First Start to Better Results at pmrsailing.uk, alongside the continuing story of A-Rater Champagne.

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Headers and Lifts — Turning Wind Shifts Into Distance

Learning to Race — From First Start to Better Results

The wind can move you twenty metres up the racecourse without making your boat any faster.

That sounds like an extravagant claim. Yet two boats can sail at exactly the same speed and make very different progress towards the windward mark.

One is sailing a favourable angle. The other is travelling just as quickly, but spending more of that speed going sideways across the course.

The difference is often a wind shift.

In the Improving Sailing series, we explored changing wind direction, reading the water and why the breeze sometimes fades when rain arrives. Now we can turn those observations into racing decisions.

Recognising a shift is useful. Understanding what to do with it is where the distance comes from.

A Lift Changes Your Direction, Not Your Height

In sailing, a lift does not mean that the wind physically lifts the boat out of the water.

When sailing upwind, a lift is a change in wind direction that allows you to steer closer to the overall direction of the windward mark while maintaining a good sailing angle to the wind.

A header, sometimes called a knock, does the opposite. It forces you to bear away from your previous heading to keep the sails working.

Imagine beating towards a buoy at the far end of the river.

Your boat is sailing comfortably, with the sails drawing and the telltales behaving. Then the wind changes.

If you can turn a little towards the mark without losing speed, you have been lifted.

If the sails begin to luff and you must turn farther away from the mark to restore their flow, you have been headed.

There is an essential qualification: these descriptions are most useful on an ordinary beat, before you have reached or passed a layline. Your position on the course still matters.

A favourable sailing angle is only useful if it takes you somewhere useful.

The Same Shift Helps One Tack and Hurts the Other

Suppose the wind initially comes from north, and your windward mark lies north of you.

For a simple example, assume your boat sails 45 degrees away from the direction the wind comes from.

On starboard tack, you head approximately north-west. On port tack, you head approximately north-east.

Now the wind shifts ten degrees clockwise, towards north-east.

Tack	Original heading	Heading after the shift	Effect
Starboard	315 degrees	325 degrees	Lift: the course is closer to north
Port	045 degrees	055 degrees	Header: the course is farther from north

The same wind shift produces opposite results.

For this straightforward upwind situation:

• A clockwise, or right-hand, shift lifts starboard tack and heads port tack.
• An anticlockwise, or left-hand, shift lifts port tack and heads starboard tack.

You do not need to memorise compass numbers immediately. Start by asking:

“Has my useful close-hauled course improved, or am I being pushed farther away?”

How a Wind Shift Can Be Worth Twenty Metres

Let us make the opening claim concrete.

Imagine two boats sailing through different local wind angles. Both travel at 2 metres per second for 80 seconds.

Each sails 160 metres through the water.

However:

• Boat A sails at 40 degrees to the direct bearing of the mark.
• Boat B sails at 50 degrees to that bearing.

Ignoring current and assuming the bearing remains approximately constant over this short comparison:

Progress towards the mark = distance sailed x cos(angle to the mark)

Therefore:

Boat A: 160 x cos(40 degrees) = approximately 123 metres

Boat B: 160 x cos(50 degrees) = approximately 103 metres

Boat A makes approximately twenty metres more progress towards the mark, despite sailing at exactly the same speed.

This is an illustration, rather than a prediction for every race. Real boats accelerate, lose speed in manoeuvres, experience current and eventually need to complete the remaining geometry of the beat.

Nevertheless, it demonstrates the principle beautifully:

Speed matters. The direction in which you use that speed matters too.

A wind shift does not instantly transport the boat twenty metres forward. Its benefit accumulates as you sail the better angle.

“Tack on Headers, Sail the Lifts”—A Useful Starting Point

When the wind swings back and forth around an average direction, sailors describe it as oscillating.

In those conditions, the familiar advice is:

Tack on significant headers and stay on useful lifts.

If you are headed on one tack, the other tack may now offer the favourable angle. When the wind swings back, the advantage can reverse.

US Sailing’s racing guidance connects sailing towards the next shift with tacking on headers in an oscillating breeze, while also distinguishing oscillating, persistent and geographical shifts. US Sailing

Picture a broad section of river with sufficient room to manoeuvre.

You are on port tack. A sustained shift forces you to bear away noticeably. There is clear water for a tack, and the other tack keeps you in reasonable breeze.

Tacking onto starboard may allow you to use the same shift as a lift.

You have not discovered extra boat speed. You have changed how efficiently you are using it.

But the word significant is doing some work here.

A brief wobble in the breeze is not necessarily worth a tack.

A Small Header Is Not an Automatic Instruction

Every tack has a cost.

The boat turns, the sails change sides, the crew moves and the boat must recover its speed. That cost depends on the boat, the conditions and the quality of the manoeuvre.

A short-lived header may disappear before the tack has paid for itself.

Before committing, ask:

1. Is this a real direction change?
2. Is it large enough, and lasting long enough, to matter?
3. Will the other tack keep us in useful wind?
4. Do we have room, and does it fit the course plan?

On a narrow river, another boat or the bank may settle the decision before the wind does.

The aim is to make fewer expensive mistakes, not to perform the greatest number of tacks.

Compare the Shift with the Average Wind

Here is a subtle point that can improve your decisions considerably.

Suppose your normal close-hauled heading on starboard is 315 degrees.

A lift allows you to sail at 325 degrees. Then the wind moves back slightly and your heading becomes 321 degrees.

You have experienced a four-degree header compared with the previous moment.

But you are still six degrees lifted compared with your normal heading.

Tacking simply because the heading became slightly worse could take you off a tack that remains favourable.

This is why experienced sailors try to establish a reference before racing.

Sail on both tacks where space allows. Notice the usual headings and the range of variation. Use a compass if you have one, or distant landmarks if you do not.

Judge the wind against a useful baseline, as well as against its last movement.

How to Recognise a Shift Without Staring at Instruments

A compass can help, but observation should extend beyond the cockpit.

Watch the sails

A genuine header may make the windward jib telltale lift or the leading edge begin to luff if you hold your course.

A lift may allow you to head up gradually while maintaining good flow and speed.

Avoid forcing the bow higher simply because you want the mark to be closer. Pinching can turn a useful lift into a slow boat.

Use a distant landmark

Choose something well ahead: a distinctive tree, roofline or other fixed feature.

If your well-trimmed close-hauled course changes relative to that feature, you have a useful clue.

A landmark shows your heading. It does not, by itself, tell you your actual track over the ground.

Watch other boats

Boats ahead may enter a new wind angle before you do.

If several boats on the same tack change heading together, take notice. A single boat turning could simply be steering poorly or avoiding traffic.

Read the water

Darker, more textured patches can indicate stronger breeze. Look for their movement and compare them with changes in boats and flags.

They are clues to investigate. They do not tell you the wind direction with certainty.

The strongest evidence comes when several observations agree.

Is It a Header—or Has the Wind Simply Faded?

This connects directly with the earlier article about rain and disappearing wind.

Your sails respond to apparent wind: the airflow resulting from the true wind and the boat’s movement.

If the true wind suddenly weakens while the boat initially retains speed, the apparent wind can move forward. The sails may behave as though you have been headed, even when the true wind direction has barely changed.

That makes this question especially useful:

“Has the wind turned, weakened, or done both?”

Look at the water. Has the texture faded? Have several boats lost power? Has your boat slowed?

An immediate tack in a lull can leave you struggling to accelerate on the other side.

First keep the boat moving, adjust trim and steering, and reassess.

Rain itself is not a reliable signal to tack. Showers and widespread frontal rain are different weather situations; the Met Office explains that showers commonly involve downdraughts, while extensive organised rain can be associated with fronts. Met Office

Your earlier observation—that the breeze often dies when rain begins—is a valuable prompt to watch more closely. It should not become a universal rule.

Oscillating and Persistent Shifts Need Different Thinking

An oscillating breeze swings around an average.

A persistent shift continues broadly in one direction during the relevant part of the race.

The distinction matters because a boat can enjoy a lift now while moving away from the side of the course that will benefit later.

If you have good evidence that the wind will continue turning, positioning towards the inside of that developing turn can become more important than immediately taking every lift. That may involve accepting a header for a time.

For a developing right-hand shift, this can favour positioning towards the right-hand side of the beat, viewed towards the windward mark. A developing left-hand shift can favour the left.

But that is a planning principle, not a guarantee.

On a river, a shift near a gap in the trees may be a local effect rather than evidence that the entire breeze is turning.

Ask:

“Is the wind swinging, trending, or changing because of where we are?”

You will not always know. Keeping options open is often sensible when the evidence is weak.

River Racing Adds Pressure, Banks and Current

A textbook diagram usually gives both boats the same wind strength and plenty of water.

The Thames does not promise either.

Imagine that one tack gives a lovely lifted heading but takes you towards smooth water beside a sheltered bank. The other is slightly headed but keeps you in stronger breeze.

The lifted route may still be slower.

Now add an adverse current. A route through stronger flow could erase the benefit of a better wind angle. Equally, moving closer to a bank for weaker current might place you in a wind shadow.

Useful progress depends on the combination of angle, speed, current and manoeuvring room.

This is why the first-beat question—“Which side should we favour?”—cannot be answered by wind direction alone.

The better question is:

“Which route gives us the best overall progress, and what evidence would make us change it?”

Aboard Champagne: Give the Crew a Shared Picture

Sailing Champagne gives me a useful way to think about this subject.

With an A-Rater’s substantial rig and three people working together, a shift is more than a change of compass number. It can affect steering, sail trim, balance and the timing of the next manoeuvre.

The opportunity is to make observation a shared task.

A simple crew conversation might be:

• Observer: “Boats ahead are heading up on starboard.”
• Helm: “We’re lifting too. Holding this tack.”
• Crew: “More pressure approaching; bank getting closer.”
• Helm: “Prepare to tack before we run out of room.”

These are examples of useful calls, rather than a recollection of a particular race.

The point is that the crew should know what the helm has noticed and what is likely to happen next.

My own sailing development makes this especially relevant. As boat handling becomes more familiar, there is more attention available for looking ahead. But noticing something is only the first step. Explaining it clearly can help the whole boat respond.

A good observation becomes more valuable when the crew can act on it together.

Try This During Your Next Practice Sail

Choose a suitable stretch of water with room to tack and manageable traffic.

Establish your normal course

Sail close-hauled on each tack. Note a typical heading or landmark alignment.

Identify changes before reacting

Say “lift”, “header” or “lull” aloud. Then check whether the sails, heading and water support that judgement.

Practise one deliberate decision

Respond to a meaningful header when there is room and useful wind on the other tack.

Notice the speed lost during the manoeuvre and how quickly the boat recovers.

Review what actually happened

Afterwards, ask:

• Was the shift temporary, persistent or local?
• Did the tack improve our progress?
• Did we leave stronger wind?
• Did current or the bank change the result?

The purpose is to connect observation, decision and outcome.

Let the Wind Help You Make Progress

There is something deeply satisfying about finding a better angle without asking the boat to sail any faster.

The sails are still drawing. The speed may be unchanged. Yet the bow is taking you somewhere more useful.

That is the opportunity offered by lifts and headers.

Learn the basic rule. Establish a reference. Notice whether the breeze is changing direction or strength. Then weigh the shift against pressure, current, traffic and the space available.

For those following Champagne and the Learning to Race series, this is another step towards anticipating the race rather than simply reacting to it.

On your next beat, ask two questions: “How fast are we going?” and “How much of that speed is taking us where we need to go?”

The second question may be worth twenty metres.

Follow the sailing articles and Champagne’s progress at pmrsailing.uk.

Return to sailing website https://pmrsailing.uk/Lessons.html

 

The First Beat — Don’t Just Follow Everybody Else

Learning to Race — From First Start to Better Results

If every boat goes left, does that mean left is correct?

The starting signal sounds. Boats accelerate, crews settle into position, and most of the fleet heads towards the same side of the course.

You follow.

It feels sensible. Some of those sailors have been racing for years. Surely they know something you don’t?

Perhaps they do. But perhaps they are following one another. Perhaps they are heading towards an advantage that has already disappeared. Or perhaps the route suits their boats better than it suits yours.

The first beat — the opening upwind leg towards the windward mark — is where racing starts to demand more than boat handling. You need to decide where to sail, what evidence supports that decision, and when to change your mind.

On a river, these choices become particularly interesting. Stronger wind might come with stronger adverse current. A sheltered bank might offer less current but almost no useful breeze. A gap between trees might provide a brief opportunity that the main group sails straight past.

The fleet is useful information. It is not an instruction.

Before Choosing a Side, Know What “Left” Means

When sailors discuss the left or right side of a beat, they normally mean left or right as you look upwind towards the windward mark.

That distinction matters on a river, where the course may run upstream in one race and downstream in another.

“The clubhouse side” might remain the same bank. “The left side” might not.

Before discussing a plan with your crew, establish a shared reference:

“Looking towards the first mark, we favour the right-hand side because the breeze looks stronger there.”

That is much clearer than discovering halfway through the leg that everyone meant something different.

The Best Route Is the One That Makes Progress Towards the Mark

A boat can look fast without making particularly good progress up the course.

It might be sailing quickly across the river, pointing poorly, or losing ground to the current. Another boat might appear quieter and slower while steadily gaining towards the mark.

Your task is to combine:

• Enough wind to keep the boat moving effectively.

• A useful sailing angle towards the mark.

• The most favourable current you can reasonably access.

• Clear air.

• Efficient manoeuvres.

The balance changes from race to race.

The RYA’s guidance on racing decisions makes a useful distinction between priorities driven by wind shifts, reaching advantageous water, and positioning relative to marks and other boats. The practical lesson is to identify what matters most at that moment.

In very light conditions, finding enough wind to move may dominate everything else. In a steadier breeze with appreciable river flow, current may become much more important.

Ask what is limiting your progress before deciding what to fix.

Where Is the Pressure?

In racing conversation, “pressure” usually means stronger wind.

Before the start, and throughout the beat, look beyond your own sails. Useful clues include:

• Patches of more strongly rippled water.

• Boats ahead heeling or accelerating.

• Changes in flags and moving foliage.

• A band of breeze travelling across the course.

Darker water can indicate stronger wind, but shadows, reflections and current can also change its appearance. Look for several clues rather than trusting colour alone.

A practical example: the fleet heads into a lull

Imagine most boats sail left after the start. Ahead of them, the water becomes smooth beneath a line of trees.

To the right, a patch of ripples is approaching. A boat already in that patch accelerates.

Following the fleet might put you into both weak wind and disturbed air. Taking a clear route towards the approaching breeze could be better.

But there is a further question:

Will the breeze reach you, or are you about to spend the next minute chasing a patch that is moving away?

Watch its movement. Sometimes holding your course allows the wind to arrive. Sometimes a modest change of position is enough. A large detour needs a larger reward.

Current — The Advantage You Cannot See in the Sails

At Upper Thames Sailing Club, on the Bourne End–Marlow reach, the river adds another layer to the problem.

The boat moves through the water. The water moves relative to the banks. Your progress towards a fixed mark depends on both.

For a simplified example, considering only the component directly towards the mark:

Progress over ground = progress through water + current towards the mark

An opposing current is subtracted.

Suppose two possible routes offer these illustrative conditions:

Route	Progress towards the mark through water	Opposing current	Progress towards the mark over ground
Open water	2.0 knots	0.8 knots	1.2 knots
Nearer the bank	1.7 knots	0.2 knots	1.5 knots

The boat nearer the bank makes better progress despite sailing more slowly through the water.

These figures are examples, not measurements from a particular Thames race. Real routes also involve changing wind angles, sideways current, tacking and different distances.

Nevertheless, they explain why judging solely by boat speed can be misleading.

Why “stay near the bank” is not a complete strategy

Current is often weaker near a bank, but the pattern depends on bends, depth, obstructions and local conditions. The same bank may also have:

• Wind shadows from trees or buildings.

• Shallow water.

• Moored boats.

• Limited room to tack.

A reduction in adverse current is valuable only if you retain enough wind and room to make use of it.

If the leg runs downstream and the flow helps you towards the mark, stronger current may become an advantage instead.

Think about what the current does to today’s leg, rather than treating one bank as permanently best.

Wind Shifts — A Good Side Can Become a Poor Side

A lift allows you to sail closer to the mark while remaining properly close-hauled. A header forces your close-hauled course farther away from it.

The temptation is to reduce this to a simple instruction: tack whenever you are headed.

That can work well in an oscillating breeze, where the wind swings backwards and forwards around a mean direction. But it is not a universal rule.

Before tacking, consider:

• Is this a real direction change, or has the boat simply slowed?

• Is the shift likely to reverse?

• Will the new tack take you into stronger wind or a lull?

• What current will you encounter?

• Is there a clear route through the other boats?

A wind direction that keeps moving one way — a persistent shift — needs different treatment from one that regularly swings back.

You do not need to master every detail immediately. Start by noticing your normal close-hauled heading on each tack, then recognise when it changes.

World Sailing’s reporting from a particularly shifty regatta illustrates the value of preserving options: sailors described both large gains from shifts and the danger of becoming trapped on one side of the course.

A practical example: a tempting lift beside the trees

You receive a lift towards the favoured bank. Your heading looks excellent, so you continue.

But the breeze becomes weaker as you approach the trees. Soon the boat loses speed and begins slipping sideways.

The lift was useful. Continuing indefinitely was not.

A favourable heading is only one part of a favourable route.

Clear Air — The Fleet’s Route May Be Good, but Your Place in It May Be Poor

The previous article considered recovering from a poor start. The first beat is where that recovery needs a purpose.

Suppose the left side really does offer better wind. Following five boats towards it may still leave you sailing in their disturbed air.

You might need to tack away temporarily, build speed in a clear lane, and return towards the favoured area when space opens.

That does not mean abandoning your strategy. It means finding a workable way to carry it out.

Aboard an A-Rater such as Champagne, the large sail plan makes airflow around nearby boats particularly relevant. It also reminds us that another boat’s route may reflect its own handling and performance characteristics.

A small dinghy making several short tacks near a bank is not automatically demonstrating the best route for Champagne.

Copying another boat’s position does not copy its conditions.

Don’t Become Contrary for the Sake of It

“Don’t follow everybody else” should not become “always go the opposite way”.

If the fleet heads left towards visibly stronger wind and weaker adverse current, there may be a very good reason to go left.

The aim is independent judgement, supported by observation.

Ask:

“What advantage are they sailing towards, and can I use it too?”

If you cannot identify a strong reason to separate, a huge split from the fleet introduces uncertainty. A route nearer the middle may preserve more options, provided it offers usable wind and clear air.

You can favour one side without committing to its extreme edge.

A River-Racing Example: Three Routes, Three Trade-offs

Imagine an upstream first beat with the wind roughly blowing down the reach.

Most of the fleet heads towards the left bank, where the adverse current appears weaker.

You have three possible approaches.

Route one: follow close to the bank.
You gain current relief, but risk weak wind beneath the trees and limited tacking room.

Route two: remain in open water.
You retain stronger breeze and more space, but face stronger opposing flow.

Route three: work along the edge of the sheltered area.
You seek some current relief while remaining far enough out to keep the sails drawing.

There is no guaranteed winner.

The third route might offer the best compromise. Then a lull could spread across it, making open water more attractive. Or the central breeze might fade, making the current relief decisive.

The skill lies in watching the trade-off develop.

Useful questions include:

“Are we still gaining against the bank?”

“Are the boats outside us making better progress towards the mark?”

“Do we have enough speed to complete the next tack?”

These questions are more productive than insisting that the original plan must have been correct.

Aboard Champagne — Give the Crew Something Useful to Notice

One of the things I find fascinating about river racing is how much there is to observe within a small stretch of water.

The next decision may depend on a gust, a gap in the trees, the movement of another boat or the flow beside a mooring. It is easy to become absorbed in handling the boat and miss the evidence developing ahead.

For Champagne, I would make the first-beat conversation specific:

“We favour the right because there is more breeze. Watch whether the boats there are actually gaining.”

The helm needs to keep the boat sailing effectively. Other crew members can contribute observations about approaching wind, traffic and relative progress.

Short calls help:

• “More breeze ahead and right.”

• “Boats near the bank have slowed.”

• “Clear water if we tack now.”

• “We are losing ground against the bank.”

“We should do something!” creates urgency without providing information.

A good crew call explains what has changed.

Make a Plan — and Give Yourself a Reason to Change It

A useful first-beat plan has three parts:

Preference: Where do we initially want to go?

Reason: What advantage do we expect there?

Review trigger: What evidence would make us reconsider?

For example:

“We favour the left for weaker adverse current. If the wind fades enough that the boats outside start gaining, we move out.”

That is a plan you can test.

“Always go left here” is much harder to learn from because it ignores why the route might work.

Before the start, sail enough of the course to investigate the conditions when time and space allow. Check both tacks, observe the current against fixed objects, and look towards the first mark.

Even a brief investigation is better than making your first assessment from inside a crowded fleet.

Learn from the Decision, Not Just the Result

After racing, ask:

1. What did we expect to gain from our chosen route?

2. What evidence did we have?

3. What changed during the beat?

4. Did we respond soon enough?

5. What would we look for next time?

A good decision can produce a disappointing result if conditions change unexpectedly. A poor decision can occasionally succeed through luck.

Finishing ahead does not prove that every choice was sound. Finishing behind does not mean there was nothing worth repeating.

The most useful reflection identifies something observable:

“We found weaker current, but stayed too long after the wind faded.”

That gives you a clear improvement for the next race.

Conclusion: Follow the Evidence

The first beat is an opportunity to start racing with intention.

Look for pressure. Understand what the current is doing. Notice shifts. Protect clear air. Consider how your own boat handles the route.

Watch the fleet, because other sailors provide valuable clues. Then ask whether their choices make sense for the conditions you can see and the boat you are sailing.

On the Thames, apparently small differences can become important: a little more breeze, a little less opposing flow, or enough room to tack without losing momentum.

You will not always choose correctly. But a decision you can explain is a decision you can learn from.

When every boat goes left, ask what they are going towards — and whether that advantage is still there.

Follow the Learning to Race series at pmrsailing.uk, alongside the continuing story of racing Champagne on the Thames.

Return to sailing website https://pmrsailing.uk/Lessons.html

 

Your Start Went Wrong — Now What?

Learning to Race — From First Start to Better Results

“A bad start costs seconds. Spending five minutes complaining about it costs much more.”

The starting signal sounds.

Unfortunately, your boat is hardly moving.

Perhaps you have arrived too early and stopped to avoid crossing the line. Perhaps another boat has closed the gap you intended to use. Perhaps you have timed everything beautifully — except that you are already over the line.

Meanwhile, the fleet sails away.

It is an uncomfortable moment. You had a plan, you could picture the perfect start, and now you are watching everyone else execute theirs.

But this is where another racing skill begins: recovering without turning one mistake into several.

A poor start can damage your result. It does not automatically decide it. There may still be wind shifts, patches of stronger breeze, changes in current and opportunities at every mark.

Your immediate job is to make the next useful decision.

1. Identify the Problem Before Choosing the Solution

“Bad start” describes several different situations, and they need different responses.

What happened?	Your immediate priority
You were over the line early	Establish what correction or penalty applies
You were squeezed out of your intended gap	Find a safe escape and room to accelerate
You crossed legally but almost stopped	Restore speed before demanding height
You started behind other boats	Assess whether you can escape their disturbed air
You arrived late	Cross correctly with speed and choose a workable first leg

The distinction matters.

If you have not started correctly, improving your position cannot solve that problem. If you have started correctly but slowly, sailing back towards the line will simply make things worse.

Ask yourself:

Have we started correctly? Are we moving? Where can we sail effectively?

Those three questions are much more useful than, “How did we get that so wrong?”

2. OCS — Correct the Start Before Chasing the Fleet

OCS means “on course side”. Broadly, it is the scoring abbreviation used when a boat has not started correctly after being on the wrong side of the line.

For an ordinary start, if you are over early, return until your entire hull is on the pre-start side, then cross the starting line correctly. An individual recall normally uses flag X with one sound; it does not identify which boats are involved. Do not assume the committee will hail your number. media.sailing.org

Know the preparatory flag. Under flag I, an infringement requires returning around an end. Z can bring a scoring penalty; U and black-flag infringements can bring disqualification that returning cannot erase. Check the sailing instructions. media.sailing.org

When returning after the signal to start or comply with the I-flag rule, keep clear of boats that are not returning until your hull is wholly on the pre-start side. media.sailing.org

Practical example: over early near the middle

Imagine crossing early near the centre of a crowded river start.

The tempting response is an immediate turn straight back into approaching boats. Instead, look for a safe route, communicate the manoeuvre and make the required correction.

Under an ordinary start, returning around an end may be a sensible route, but it is not automatically required. Under the I-flag rule, it matters.

Once you have restarted, resist the urge to recover every lost metre immediately.

Complete the correction, settle the boat and begin racing again.

3. Squeezed Out — Stop Fighting for a Gap That Has Disappeared

A space that looked generous twenty seconds ago can become remarkably small.

A boat to leeward comes up. A boat to windward closes in. You lose room to bear away and accelerate. Your sails begin to flap, and suddenly your excellent starting position contains a boat with very little speed.

The costly response is to keep defending the original plan after it has stopped working.

You may need to:

• Ease out behind another boat.
• Bear away slightly where there is safe space.
• Tack into an available lane once you can do so safely.
• Accept a later crossing at a less crowded part of the line.

None of these manoeuvres gives you permission to force a gap or ignore the boats around you.

Practical example: the crowded favoured end

You aim for the favoured end, but several other sailors have reached the same conclusion.

At ten seconds to go, there is no realistic space to accelerate.

A controlled escape and a slightly later start in roomier water may cost less than remaining trapped beside the mark.

The favoured end is only valuable if you can use it.

A small positional advantage can disappear very quickly when the boat cannot move.

4. Stalled Boat — Speed First, Height Second

After a slow start, the first mark can become an obsession.

You point towards it, pull the sails in and try to climb to windward. Unfortunately, a boat with little speed cannot necessarily sail that high effectively.

It may make leeway while feeling as though it is pointing beautifully.

Where space allows, bear away a little, adjust the sheets to the new course and let the boat accelerate. Then bring her gradually back towards an efficient close-hauled course.

Think:

Build speed. Establish flow. Then ask for height.

Avoid large, repeated rudder movements. They add drag precisely when you are trying to regain momentum.

Return to the Five Essentials

This is a good moment to use familiar boat-handling foundations:

• Sail setting: Are the sails appropriate for the course and wind?
• Balance: Is excessive heel making the boat harder to sail?
• Trim: Is crew position helping the boat move efficiently?
• Centreboard: Is its position suitable for this leg and boat?
• Course made good: Are you actually progressing towards the mark?

Poor starts often encourage rushed handling. Returning to the essentials gives the crew something useful to do.

On Champagne, the recovery plan needs to account for the space and time required to complete a manoeuvre and accelerate. There is little value in borrowing a manoeuvre from a small dinghy if the available gap does not suit the A-Rater.

5. Dirty Air — Do Not Spend the Whole Beat Following Someone’s Stern

You have started correctly. You have some speed. But the boat ahead keeps pulling away.

Its sails disturb the wind reaching yours. Your sails may still look reasonably full, yet the boat feels less powerful and struggles to hold its course.

Before blaming the trim, consider your position relative to the other boats.

Can you find a lane with clearer air?

Possible routes include bearing away briefly into space, continuing until a lane opens, or tacking when there is enough room and a useful destination.

However, tacking is a manoeuvre, not a guaranteed cure.

It may put you beneath another boat, towards a sheltered bank or into stronger adverse current. Look at where you will end up before you turn.

Practical example: behind a larger boat

A dinghy starting behind an A-Rater may find the disturbed air particularly troublesome. The larger sail plan makes clear air an important consideration.

Equally, aboard Champagne, being trapped behind another boat still demands a decision about space, wind and the next manoeuvre.

The useful question is:

“Where can our boat sail properly for the next minute?”

That may matter more than being momentarily closer to the mark.

6. Late Start — Use the Space You Have Been Given

A late start is frustrating, but it can leave you with something the crowded front row lacks: space.

Use it.

Cross the line correctly, with the boat moving well. Look ahead at the fleet and identify which lanes are blocked, which boats are struggling and where the next patch of breeze appears to be.

Do not turn lateness into frantic steering.

Practical example: ten seconds behind

Suppose you reach the line ten seconds late, but at good speed in relatively clear air.

Ahead, several boats are interfering with one another. One is pinching, another is forced into a tack, and a third is trapped in disturbed wind.

You are behind, but you can still sail efficiently.

That does not make lateness desirable. It means the situation contains an opportunity as well as a loss.

Use the race you now have, rather than trying to recreate the start you wanted.

7. River Recovery — Clear Air Is Only Part of the Answer

On the Thames, the route back into contention is rarely just “tack away”.

Banks, trees, buildings, bends and current can all influence whether that move helps.

Moving towards a bank may reduce adverse current, but it may also take you into weaker wind. Staying farther out may offer stronger breeze while exposing you to more current.

These are observations to make on the day, not fixed rules about which side is always best.

A simple way to think about it is:

Speed over the ground = boat velocity through the water + current velocity

Direction matters: current can help, oppose or carry you sideways.

For a simplified straight-line example:

• Boat A makes 2.0 knots towards the mark through the water, against 0.8 knots of current: progress is 1.2 knots.
• Boat B makes 1.6 knots towards the mark, against 0.2 knots of current: progress is 1.4 knots.

Boat B moves more slowly through the water but progresses faster towards the mark. The figures are illustrative, and real sailing also involves course angle and leeway.

After a bad start, look beyond the nearest rival. Ask where the boat can make the best useful progress.

8. Change the Crew Conversation

A poor start can become a surprisingly long conversation.

“We should have gone earlier.”

“That gap was never there.”

“Why did we tack?”

Meanwhile, nobody is watching the next gust.

Aboard a boat such as Champagne, useful communication can divide attention between sailing the boat, observing nearby traffic and assessing the next opening.

Keep calls short and actionable:

• “We need speed.”
• “Boat approaching on starboard.”
• “No safe tack yet.”
• “Clear lane opening.”
• “Pressure ahead.”
• “We have restarted — next decision.”

There is a place for discussing responsibility and improving the process. It is usually after the race.

During recovery, the crew needs shared awareness more than a detailed reconstruction of the mistake.

9. Personal Reflection — Make the Next Decision Worth Having

Suggested first-person passage for Philip to adapt:

For me, part of the appeal of racing Champagne is that it gives boat handling, observation and teamwork a very clear purpose. We can have an idea of what we want to do, but the wind and the boats around us still demand decisions.

The attitude I want to develop is simple: acknowledge a mistake without allowing it to occupy the rest of the race.

If a start goes wrong, I want our next conversation to be about getting the boat moving, finding room and recognising the next opportunity. There will be time ashore to ask what we should have done differently.

That is also what makes racing such a useful learning experience. We are learning how to respond when the plan stops fitting the situation.

10. Recover in Stages — Avoid the Desperate Gamble

After a bad start, it is tempting to head to the opposite side of the course simply because everyone else has gone the other way.

Occasionally, a different route pays handsomely. But being behind is not evidence that the empty side has better wind.

Make a change for a reason:

• You can see stronger breeze.
• You have identified a useful shift.
• You can reduce adverse current.
• You can escape prolonged disturbed air.
• You can approach the next mark with fewer complications.

Otherwise, concentrate on achievable gains.

Sail the next minute well. Make the next tack cleanly. Plan the next rounding early. Reduce the gap to the next boat.

A useful recovery target might be:

“By the first mark, we want clear air, good speed and a controlled approach.”

That is something the crew can work towards. “We must catch everyone immediately” is much less helpful.

11. Practise Recovery Before You Need It

Recovery can be trained deliberately.

In an organised practice session, try starting five or ten seconds behind another boat. Concentrate on building speed and finding a usable lane.

Alternatively, practise slowing near an imaginary line, then accelerating towards a target. Notice how much room your boat needs and how early the sails and crew must be ready.

For a crewed boat, rehearse the words as well as the manoeuvres.

Who checks traffic? Who watches the line? Who calls the next opening?

Keep exercises clear of other racing boats and unsuitable traffic. The purpose is to build judgement, not manufacture a crowded incident.

12. Debrief One Cause and One Improvement

After the race, replace “That was a terrible start” with a more precise diagnosis.

Were you:

• Too early and forced to stop?
• Too late beginning the final approach?
• Dependent on a gap that closed?
• Uncertain of the line position?
• Slow because the boat was poorly set up?
• Slow to recognise disturbed air?

Choose one improvement for the next race.

For example:

“We stopped too close to the line. Next time we will leave more room for acceleration.”

Or:

“We stayed trapped too long. Next time we will identify an escape route earlier.”

Specific changes turn frustration into progress.

The Start Is Important — So Is Everything Afterwards

Some starts are costly. Some penalties cannot be repaired by returning. A short race may leave little time to recover.

But a legal, disappointing start still leaves you with decisions to make.

You can spend the next five minutes explaining why you are behind, or you can spend them sailing the boat effectively, reading the river and looking for opportunities.

You may not recover every place. You can still recover your concentration, your teamwork and the quality of your sailing.

The starting signal tells you when the race begins. It does not tell you how the race will end.

Follow the Learning to Race — From First Start to Better Results series at pmrsailing.uk, exploring club racing, river tactics and the continuing adventure of sailing Champagne.

Return to sailing website https://pmrsailing.uk/Lessons.html

 

Clear Air — The Most Valuable Thing on the Start Line

PMR Sailing | Learning to Race — From First Start to Better Results

Sometimes being two metres behind is faster than being one metre ahead.

spinsheet.com

Picture the scene. You are approaching the starting line with ten seconds remaining. You have judged your distance reasonably well, your sails are set, and you are moving towards the line with what appears to be a very good chance of starting ahead of several other boats.

The starting signal sounds.

You cross the line almost perfectly, perhaps even a metre ahead of your nearest competitor.

Excellent! Or is it?

Within thirty seconds, something strange happens.

The boat immediately to windward of you begins moving ahead. Your sails are full, but the boat no longer seems to accelerate properly. You pull the sails in slightly, hoping to point higher, but that only makes matters worse.

Your competitor, who crossed the line two metres behind you, is now sailing faster, pointing higher and moving steadily ahead.

What went wrong?

You had a good start in terms of timing and position, but a poor start in terms of airflow.

You were sailing in disturbed air, often called dirty air, while your competitor had managed to find clear wind.

It is one of the most important lessons in sailboat racing, and one that can make an enormous difference on the relatively narrow waters of the River Thames.

1. A Sailing Boat Needs More Than Just Wind

When we learn to sail, we quickly discover that the sails must be adjusted according to the direction of the wind.

Sailing close-hauled, we trim the sails in. Sailing on a reach, we ease them out. On a run, the sails are eased much further.

As sailors progress, they begin to appreciate that it is not simply the strength of the wind that matters.

The quality of the airflow is equally important.

A sailing boat performs best when its sails are receiving an appropriate, reasonably steady airflow. That allows the sail to develop the aerodynamic forces needed to drive the boat forwards.

When another boat interferes with that airflow, three things can happen:

• The wind reaching your sails may be weaker.

• The direction of the wind reaching your sails may change.

• The airflow may become more turbulent and less consistent.

Any combination can reduce your boat speed.

You may still feel wind on your face. Your sails may still appear reasonably full. Yet your boat is no longer performing as well as it should.

This is particularly noticeable when sailing upwind, where even a small loss of boat speed or pointing ability can have a significant effect on your progress towards the windward mark.

2. What Exactly Is Dirty Air?

marconyachting.com

Imagine two boats sailing close-hauled towards the windward mark.

The first boat is sailing through relatively undisturbed wind. Its sails alter the airflow around them, producing the aerodynamic forces that move the boat.

However, the air leaving those sails is not exactly the same as the air approaching them.

The airflow has changed direction, and the boat has created a disturbed region around and downwind of its rig.

The second boat may find itself sailing through some of this disturbed air.

Its sails are now receiving air that has already been affected by the first boat.

The result is what sailors call dirty air.

A wind shadow is not quite the same as a shadow on the ground

When a tree casts a shadow, we can see where sunlight has been blocked.

Wind is different.

A sail does not simply stop the wind. It changes the speed and direction of the surrounding airflow.

Therefore, the wind shadow of a sailing boat is not a perfectly defined area directly behind the sail.

Its location and strength depend on:

• Wind direction and strength.

• The angle at which the boats are sailing.

• The size and shape of the sails.

• The distance between the boats.

• The relative positions of the boats.

• The surrounding wind conditions.

The important lesson is that the disturbed air may affect another boat even when that boat is not directly behind the first one.

On an upwind leg, a boat can suffer from disturbed airflow while sailing slightly to windward and astern of another boat.

This is one reason why the starting line can become so tactically complicated.

3. Why Dirty Air Can Ruin an Apparently Perfect Start

Let us consider two boats, A and B, sailing upwind on the same tack.

Boat A crosses the starting line slightly ahead.

Boat B starts a couple of metres behind but has a clear lane, allowing its sails to work efficiently.

Initially, A appears to have the advantage.

However, suppose Boat A is close to another boat whose sails are disturbing the wind reaching A.

Boat A loses a little speed. The helm tries to maintain the same pointing angle, but the sails are no longer producing the necessary driving force.

The crew may then have to bear away slightly to rebuild speed.

Boat B, meanwhile, continues sailing in clear air.

It accelerates, maintains a better speed and may be able to sail a more effective course towards the windward mark.

Within a surprisingly short distance, Boat B can overtake Boat A.

That is the meaning behind our opening statement:

Sometimes being two metres behind is faster than being one metre ahead.

Of course, a boat two metres behind is not automatically in clear air. Everything depends on its position relative to the wind and the surrounding boats.

The important question is not simply who crossed the line first.

It is who can sail fastest, on the most useful course, during the first minute after the start.

4. Why the First Minute Is So Important

The moments immediately after the starting signal are often among the most important in an upwind race.

Boats are close together. Everyone is accelerating. Most competitors are attempting to establish a position from which they can sail towards the windward mark.

At this point, three advantages become particularly valuable:

Boat speed: You want to accelerate quickly and then maintain your normal racing speed.

Pointing ability: You want to sail effectively towards the windward mark without being forced to sail lower than necessary.

Freedom of movement: You want enough space to respond to wind shifts and make tactical decisions.

Dirty air can damage all three.

A boat that loses speed may find itself slipping back into even more disturbed air from the boats ahead.

The sailor then faces a difficult choice.

Remain on the current course and hope conditions improve, or tack away and try to find clear wind?

The longer the decision is delayed, the more difficult the situation can become.

This is sometimes described as being trapped in a bad lane.

A good lane is not simply an empty piece of water.

It is a position where you can sail at full speed for a useful distance without being forced to alter course unnecessarily.

5. The Invisible Battle Between Windward and Leeward Boats

There is another fascinating feature of dirty air.

It does not always affect the windward and leeward boats in the same way.

When two boats are sailing close-hauled alongside each other, each can influence the airflow reaching the other.

A boat sailing to leeward may disturb the airflow around the windward boat, producing an unfavourable change in the apparent wind that makes it difficult for the windward boat to maintain its course and speed.

Sailors often call this the lee-bow effect.

Conversely, a boat to windward and slightly ahead may place the leeward boat in its wind shadow.

Which boat gains the advantage depends on their relative positions, sail configurations, wind strength and how effectively each boat is being sailed.

In light winds, the aerodynamic interference may extend further and have a particularly significant effect on performance.

Bloomsbury

+2

A practical example

Suppose you are sailing close-hauled on starboard tack, with another boat slightly ahead and to leeward.

You may be tempted to point higher to get past.

However, if the other boat is disturbing the airflow reaching your sails, attempting to point even higher could make matters worse.

Your boat loses speed and the other boat moves further ahead.

In this situation, the correct response may be to bear away a little to rebuild speed, provided doing so gives you room and useful airflow.

Alternatively, a tack into clear air may offer a better opportunity.

The important skill is recognising when your boat is genuinely slow because of its trim, and when it is slow because another boat is interfering with the wind.

That distinction takes practice.

6. Why Clear Air Matters Even More on the River Thames

pmrsailing.uk

On open water, a sailor who finds themselves in dirty air may have plenty of room to tack away, sail into clear wind and establish a new position.

River sailing can be rather different.

At Upper Thames Sailing Club, we race on a river bordered by trees, buildings and varying bankside vegetation.

The wind is rarely as straightforward as the forecast might suggest.

Even before another sailing boat interferes with it, the airflow may have been disturbed by the landscape.

Trees can create sheltered areas and turbulence. Gaps between trees may allow stronger gusts to reach the water. The direction of the wind may vary considerably across the width of the river.

Now introduce a fleet of racing dinghies.

Each boat creates its own area of disturbed airflow.

Suddenly, finding clear air becomes a rather more complicated exercise.

The riverbank problem

Imagine that the best wind is currently towards one bank.

Naturally, several sailors decide to sail towards that side of the river.

The boats become concentrated in a relatively small area.

The leading boat may be enjoying reasonably clear wind, but the boats immediately behind begin interfering with each other's airflow.

A sailor who remains a few metres further out towards the centre of the river may have slightly less wind pressure but considerably cleaner airflow.

That sailor might consequently make better progress.

However, there is another complication.

The River Thames has a current.

An attractive piece of water may offer good wind but an unfavourable current. Another part of the river may offer slightly worse wind but more favourable water movement.

Therefore, the best racing decision involves balancing three factors:

Wind strength + Wind quality + River current

And, of course, the distance you need to travel.

The fastest route is not necessarily the shortest route, nor is it automatically the route with the strongest wind.

It is the route that gets you to the next mark in the least time.

A personal reflection

One of the things I find particularly interesting about sailing on the Thames is that you can experience completely different wind conditions within a surprisingly small area.

It encourages constant observation.

I might look at the wind indicator, the movement of the water and the sails of nearby boats, all while trying to work out whether there is a better route towards the next mark.

It also makes me think more carefully about other boats.

Rather than simply asking, "Can I get ahead of that boat?", I find the more useful question is often:

"Where will I have the clearest wind in thirty seconds?"

That is a small change in thinking, but an important one in the transition from simply sailing a race to racing intelligently.

7. A-Raters and the Enormous Influence of Sail Area

This subject becomes particularly interesting when we consider an A-Rater such as our own Champagne.

An A-Rater is a very different proposition from an ordinary training dinghy.

Its long, narrow hull, lightweight racing construction and particularly tall rig are designed to produce excellent sailing performance.

The large sails create the aerodynamic forces needed to drive the boat at impressive speeds.

But those sails also influence the airflow around the boat.

Why a large sail creates a significant wind shadow

A large, efficient rig interacts with a substantial volume of moving air.

As the sails generate aerodynamic forces, they alter the flow around and downstream of the rig.

This can produce an extensive area of disturbed air that affects smaller boats sailing nearby.

It is tempting to imagine that a sail twice the size automatically creates a wind shadow twice as long.

That is not how it works.

The affected area depends on sail geometry, wind conditions, relative positions and other aerodynamic effects.

Nevertheless, a large racing rig can create a substantial wind shadow, particularly in lighter conditions.

For a smaller dinghy sailing close behind an A-Rater, this can be extremely frustrating.

The smaller boat may be sailing perfectly well, with sails correctly trimmed and crew weight sensibly positioned.

Yet it can lose speed simply because it is sailing through air disturbed by the larger boat.

Champagne approaching a crowded starting line

Imagine we are approaching the starting line in Champagne.

Ahead of us are several smaller racing dinghies.

Our immediate objective is to make a good start, accelerate cleanly and establish a useful position.

However, we must consider more than the position of our bow.

We need to think about the effect of our rig on neighbouring boats, and the effect of their sails on our own airflow.

Although our rig is particularly tall, it is not immune to disturbed wind.

Another A-Rater positioned poorly relative to us could interfere with the wind reaching our sails.

And in the light, variable conditions frequently encountered on the river, even a relatively small reduction in effective wind can make a noticeable difference.

A boat that depends on maintaining momentum does not benefit from being repeatedly slowed by disturbed air.

The sailing team must therefore consider both the immediate start and the conditions the boat will encounter during the first part of the race.

Teamwork aboard Champagne

This is where sailing an A-Rater becomes particularly rewarding.

With three people aboard, we have an opportunity to divide our attention between different aspects of the race.

One person may be concentrating primarily on steering and maintaining speed.

Another can concentrate on sail trim and the information provided by the tell-tales.

The third can help observe surrounding boats, wind shifts and potential areas of clear air.

The precise division of responsibilities will vary with conditions and experience, but the principle remains valuable.

Good racing is not simply about steering quickly. It is about ensuring that the whole crew understands what is happening around the boat.

A useful communication might be:

"Boat ahead is disturbing our wind. Clear air to starboard if we can find room to tack."

Or:

"Keep this lane. We have good pressure and the boats behind are dropping away."

These observations help the helm make decisions without having to look everywhere at once.

8. How to Find Clear Air Before the Starting Signal

The best way to escape dirty air is often to avoid entering it in the first place.

That begins before the starting signal.

Look beyond the starting line

Many inexperienced racing sailors concentrate almost entirely on the line itself.

They are thinking about whether they will cross too early or too late.

More experienced sailors also consider what happens immediately afterwards.

Before committing to a starting position, ask yourself:

• Which boats are likely to be directly ahead of me after the start?

• Will I have room to accelerate?

• Am I likely to be trapped between two boats?

• Can I sail towards the favoured side of the course?

• If I lose my wind, is there an escape route?

The last question is particularly important.

A start may appear excellent until the boats on either side prevent you from doing anything useful.

Avoid the temptation to join the crowd

Suppose the committee-boat end of the starting line is favoured by a small amount.

Naturally, many boats are likely to gather there.

It might seem sensible to join them.

But if the result is a tightly packed group in which you cannot accelerate properly, the theoretical advantage of starting at the favoured end may disappear.

Starting slightly further down the line, in a position where you have room and clear air, could be considerably better.

This does not mean you should ignore line bias.

Rather, you should understand that line bias is only one part of the starting decision.

You need to weigh it against your ability to sail at full speed after the starting signal.

That balance is an established principle of racing-start strategy.

Bloomsbury

+2

9. A Simple Example: The Crowded Start and the Clear Start

Let us imagine a race with twelve boats.

The starting line is relatively short, and the wind is light.

There are two possible approaches.

Start A: Crowded

Boats tightly packed, with little room to accelerate or escape

Start B: Clear lane

More space to accelerate and maintain boat speed

Simplified conceptual diagrams, not to scale. Actual disturbed-air patterns depend on wind direction and boat position.

In Start A, a boat crosses the line almost exactly on time but is surrounded by other boats.

It cannot accelerate freely. The sails are affected by disturbed air. It has limited room to change course.

In Start B, a boat crosses the line two seconds later but has a clear lane.

Suppose, purely for illustration, that:

• The crowded boat averages 2.5 knots during the first minute.

• The clear-air boat averages 3.5 knots during the same period.

Converting knots into metres per second:

Speed in metres per second = Speed in knots x 0.5144

Distance travelled = Speed x Time

Over 60 seconds:

Crowded boat = 2.5 x 0.5144 x 60 = 77.2 metres

Clear-air boat = 3.5 x 0.5144 x 60 = 108.0 metres

Illustrative distance travelled in 60 seconds

0 m30 m60 m90 m120 mCrowded boatClear-air boat

Assumes constant illustrative speeds; actual results vary.

The clear-air boat travels approximately 31 metres further through the water, before allowing for its later starting time, headings or current.

A two-second starting disadvantage at 3.5 knots represents only about 3.6 metres of travel.

If the faster boat can maintain its speed advantage, that initial disadvantage can disappear very quickly.

Naturally, real racing is more complicated. Both boats may be travelling in slightly different directions, and changing current or wind conditions can alter the result.

Nevertheless, the principle is clear.

A few metres gained at the start are of little value if you immediately lose the ability to sail quickly.

10. What Should You Do When You Find Yourself in Dirty Air?

Even experienced racers sometimes end up in poor air.

Perhaps another boat tacks ahead of them.

Perhaps they underestimate the wind shadow of a larger boat.

Or perhaps the wind changes direction, leaving them in a position that was perfectly acceptable only a few seconds earlier.

The important thing is to recognise the problem and respond intelligently.

Option 1: Sail into clear air

Sometimes only a modest change in position is needed.

If there is sufficient room and the course allows it, you may be able to bear away slightly, accelerate and sail clear of the disturbed airflow.

However, this is not always possible.

On a narrow river, sailing lower may put you close to the bank or another competitor.

Option 2: Tack away

If you cannot escape while remaining on the same tack, changing tack may be the best solution.

A tack costs some speed, particularly in light wind.

But continuing for several minutes in disturbed air may cost considerably more.

The decision involves comparing the short-term loss of speed during the tack with the potential longer-term benefit of sailing in clear wind.

You must also consider the racing rules, other boats and whether your new course will take you towards a useful part of the river.

Option 3: Wait for a change

Sometimes there is no sensible immediate escape route.

You may be close to a mark, constrained by other boats or expecting a useful wind shift.

In these circumstances, remaining where you are briefly may be preferable to making a hurried manoeuvre.

However, waiting should be a deliberate tactical decision rather than simply hoping that the problem will disappear.

Option 4: Protect your lane

Perhaps the most effective tactic is not allowing another boat to place you in bad air.

Look ahead.

Anticipate where nearby boats are likely to sail.

Where possible, preserve enough space to keep moving at full speed.

That is often easier than recovering after you have already lost momentum.

11. Three Common Mistakes Beginners Make

Mistake 1: Trying to point higher when the boat is already slow

A sailor notices that another boat is getting ahead and responds by pulling the sails tighter and turning closer to the wind.

Unfortunately, if the sails are already struggling in disturbed airflow, this can make the problem worse.

The boat slows further and may begin to make considerable leeway.

Better approach: Check your tell-tales, assess your speed and consider whether you need to bear away slightly to rebuild momentum.

Mistake 2: Staying directly behind a larger boat

A smaller dinghy may follow a larger boat upwind, hoping to benefit from its chosen route.

But the smaller boat may find itself continually sailing in disturbed air.

Better approach: Look for an opportunity to establish a separate lane with clear wind rather than simply following another boat.

Mistake 3: Winning the starting line but losing the first beat

An inexperienced racer may be delighted to cross the line ahead of the fleet.

But the real objective is not to be ahead for one second.

It is to establish the speed, position and freedom to make good progress towards the first mark.

Better approach: Judge your start by where you are thirty seconds or a minute later, not simply by your position when the starting signal sounds.

12. A Practical Exercise to Try at Your Sailing Club

Understanding dirty air becomes much easier when you experience it deliberately.

This exercise is suitable for two comparable boats and can be used during a coaching session in an appropriate area of open water, away from other traffic.

Exercise 1: Sail side by side

Start with the boats sailing upwind on the same tack, separated by a generous safe distance.

Gradually vary their relative positions, while maintaining safe separation, and observe changes in boat speed, heading and tell-tale behaviour.

Try repeating the exercise in different wind strengths.

Exercise 2: Follow another boat

Have one boat follow another at a safe distance, initially in a position where the following boat experiences disturbed air.

Observe the change in speed.

Then allow the following boat to move into a clear lane and compare its performance.

Exercise 3: Two practice starts

Set up a short practice starting line.

On the first attempt, concentrate on crossing as close as possible to the starting signal.

On the second attempt, concentrate on establishing clear air and maintaining speed.

Compare the relative positions after one minute rather than only at the start.

These exercises should be undertaken with suitable supervision, clear separation and proper regard for other river users. There is no need to position boats dangerously close together to demonstrate the effects.

What should you observe?

Ask the sailors to notice:

• Whether their sails require different trimming in disturbed air.

• How quickly the boat accelerates when it finds clear wind.

• Whether the boat can maintain its pointing angle.

• How strongly the effect varies with wind speed.

• How long it takes to recover speed after escaping the wind shadow.

If you have access to GPS tracking or suitable boat-speed instruments, it may be possible to compare the results more quantitatively.

Even without instruments, the exercise can be remarkably revealing.

A sailor who has experienced the frustration of being trapped in dirty air is much more likely to recognise the same situation during a race.

13. What the Best Racers Are Really Watching

When watching an experienced sailor preparing for a start, it is easy to assume that they are concentrating entirely on the countdown.

In reality, they may be watching several things simultaneously.

They are assessing line bias, looking for wind shifts, judging boat speed and deciding how much room they need to accelerate.

But they are also watching the surrounding boats.

They want to know who is likely to accelerate first, who might tack, which gaps are closing and where they will find clear air after the start.

This is a particularly useful lesson for those progressing from recreational sailing into racing.

At first, we learn how to control our own boat.

Then we learn how to observe the wind and water.

Eventually, we begin to appreciate that every other boat is influencing the conditions around us.

That is when sailing becomes a much more interesting tactical activity.

14. Five Things to Remember About Clear Air

1. A perfect start is not necessarily the earliest start. Crossing the line on time is valuable only if you can maintain speed afterwards.

2. Dirty air can affect boats alongside as well as behind. It is not simply a neat shadow extending directly downwind.

3. Light winds make clear air especially valuable. Losing pressure in already marginal conditions can have a substantial effect on performance.

4. A crowded favoured end may be worse than a clear lane elsewhere. Always balance starting-line advantage against the ability to accelerate and sail freely.

5. Think ahead rather than react too late. It is much easier to avoid bad air than to recover after several boats have passed you.

Conclusion: The Race Begins with the Wind You Can Actually Use

There is something rather satisfying about crossing the starting line ahead of the rest of the fleet.

For a brief moment, you may feel that you have everything exactly right.

But racing success is rarely decided by a single moment.

A sailing race is a continuous sequence of decisions, and the most valuable starting position is often the one that gives you the best opportunity to make your next decision.

A good start provides more than a favourable position.

It provides clear wind, boat speed and freedom of movement.

On the River Thames, where the wind is constantly being influenced by the trees, banks and surrounding boats, these advantages can be particularly valuable.

And when sailing a powerful, large-rigged A-Rater such as Champagne, understanding how the sails influence the surrounding airflow becomes another fascinating part of racing.

It is easy to become preoccupied with gaining that final metre on the starting line.

But perhaps we should ask a different question.

Would I rather be one metre ahead, struggling in disturbed air, or two metres behind with room to accelerate into clear wind?

I know which I would prefer.

The best start is not always the one that puts you ahead at the gun. It is the one that gives you the best chance of being ahead at the first mark.

Follow the Learning to Race series at PMR Sailing, where we explore practical racing skills, sailing on the River Thames and our experiences aboard the A-Rater Champagne.

Return to sailing website https://pmrsailing.uk/Lessons.html