Crossing Another Boat — Tack, Duck or Keep Going?
Learning to Race — From First Start to Better Results
Sometimes the fastest tactical move is deliberately sailing behind somebody.
You are sailing upwind, the boat feels settled, and there is a promising patch of wind ahead. Then another boat appears on the opposite tack.
The distance between you begins to close.
Can you cross ahead? Should you tack? Or would it be better to bear away slightly and pass behind?
For a developing racing sailor, this can feel like a test of nerve. Passing ahead seems like winning; passing behind seems like losing.
But a crossing is really a decision about where your boat will be sailing next.
A small duck behind another boat might preserve your speed, keep you heading towards stronger wind and avoid two unnecessary tacks. An apparently successful crossing might take you straight into a wind shadow beside the bank.
The aim is to make the crossing serve your race strategy.
First, Understand Who Must Keep Clear
For ordinary crossings between racing boats, the essential starting points in the 2025–2028 Racing Rules of Sailing are:
Opposite tacks: port keeps clear of starboard — Rule 10.
Same tack, overlapped: windward keeps clear of leeward — Rule 11.
Same tack, no overlap: the boat astern keeps clear — Rule 12.
While tacking: after passing head to wind, a boat keeps clear until reaching a close-hauled course — Rule 13.
Right of way has limits. Rule 14 requires avoiding contact when reasonably possible. Under Rule 16.1, a right-of-way boat changing course must give the other boat room to keep clear. Rule 15 generally requires room initially when acquiring right of way.
On a beat, Rule 16.2 also restricts a starboard boat bearing away when port is already keeping clear by passing to leeward, if that would force port to change course immediately.
These are summaries; marks and obstructions introduce further rules.
For the tactical examples below, imagine an ordinary upwind crossing, away from marks and obstructions, with your boat on port tack.
Spot the Crossing Before It Becomes Urgent
The best crossing decisions begin while the boats are still comfortably separated.
Look beyond your own bow. Where is the other boat heading? Is she accelerating in a gust? Will your own boat soon enter lighter wind?
A useful warning sign is another boat remaining in roughly the same direction relative to you while getting closer. That suggests a possible collision course.
However, this is an observation to keep updating, rather than a guarantee. Sailing boats change speed and heading, particularly on a sheltered river.
A gap that looked comfortable can disappear when:
Your boat enters a lull.
The other boat receives a gust.
A wind shift changes the crossing angle.
One crew sails through a patch of disturbed air.
On Champagne, looking around the large sail plan is part of the job. A crew member who watches approaching boats can give the helm valuable time.
“Starboard boat approaching; crossing looks doubtful” is useful information while there is still space to choose a sensible response.
Option One: Keep Going When the Crossing Is Clearly Safe
If you can pass comfortably ahead while keeping clear, continuing may be the best choice.
You preserve your speed, avoid a manoeuvre and stay with your plan.
The important word is comfortably.
A crossing should have enough margin for the conditions and the boats involved. A smooth-water judgement between evenly paced dinghies may be inappropriate when boats differ greatly in length, speed or handling.
Think about the whole boat, too. Your bow passing ahead does not mean your stern has cleared.
A Thames example
Imagine Champagne approaching on port tack. There is useful pressure towards the part of the reach you want to sail, and the approaching starboard boat will pass clearly behind your stern.
Continuing makes sense.
Now imagine the same crossing with Champagne losing speed in a lull. The original judgement needs revisiting immediately.
A good decision made ten seconds ago can become a poor decision if you stop looking.
There is also a strategic question: once you have crossed, are you still sailing towards somewhere useful?
Passing ahead is satisfying. Sailing into a long patch of weak wind immediately afterwards is less so.
Option Two: Duck Behind and Preserve Your Plan
A duck is a controlled alteration away from the wind to pass behind another boat, followed by a return towards your intended course once safely clear.
It can be one of the most useful manoeuvres in fleet racing.
You accept a small, immediate loss in order to preserve something more valuable:
Boat speed.
Access to stronger wind.
A favourable current lane.
Separation from the fleet.
Freedom to choose your next tack.
Why passing behind can be faster
Imagine you want to continue towards a visible patch of stronger wind. A starboard boat is approaching, and you cannot cross safely ahead.
You could tack. But that sends you away from the pressure. To return to your original plan, you may soon need to tack again.
Alternatively, a modest duck may let you continue towards the wind you wanted.
You have passed behind one boat, but you may have improved your prospects against several others.
A local loss can buy a larger strategic gain.
Half a Boat Length Versus Two Tacks
Suppose, purely as an illustration, a smooth duck costs about half a boat length of progress compared with an unobstructed course.
Now suppose tacking away and then tacking back costs roughly one boat length per tack through turning and rebuilding speed.
The comparison becomes:
Duck: about 0.5 boat lengths lost.
Two tacks: about 2 boat lengths lost, before considering where they take you.
Those figures are deliberately illustrative. Actual losses depend on the boat, crew, wind, water and execution. A deep duck can be expensive; an excellent tack can be economical.
The lesson is to compare the whole sequence.
Do not compare one duck with one tack if the tack will force another manoeuvre shortly afterwards.
For Champagne, this is a particularly useful question in light winds: how much speed will we retain, and how much will we have to rebuild?
How to Make a Duck Work
A good duck begins with a decision made early enough to execute smoothly.
Check the space beyond the first boat
Before bearing away, look behind and to leeward of the approaching boat.
There may be another competitor following her. There may also be a moored boat, shallow water or a bank limiting your route.
A gap behind the first boat is only useful if it leads somewhere safe.
Bear away enough to make the intention clear
Allow a sensible margin behind the stern. Avoid turning the manoeuvre into a last-second attempt to squeeze through.
The helm and crew should coordinate sail trim with the altered heading. Depending on the boat and the size of the alteration, some easing may help the boat turn and keep moving efficiently.
Keep watching the other boat
Do not stare only at the water immediately ahead of your bow.
Watch the other boat’s stern, speed and heading, while maintaining awareness of the surrounding fleet.
Return smoothly once safely clear
An abrupt turn back towards the wind can waste the speed you worked to preserve.
Allow for the whole of both boats, then return smoothly towards your intended heading and trim accordingly.
You may briefly encounter disturbed air during the manoeuvre. Avoid assuming that passing behind automatically gives you clear wind.
The objective is a safe crossing followed by an efficient exit.
Option Three: Tack When the New Tack Helps You
Ducking is useful, but it should not become an automatic response.
Sometimes the approaching boat gives you a good reason to make a tack that already suits your strategy.
Tacking may be attractive when:
The new tack leads towards better pressure.
You are approaching the useful limit of the reach.
Continuing would take you towards a wind shadow.
A duck would require a large diversion.
Several boats make the route behind difficult.
The new tack offers a good lane of clear air.
A different Thames example
Imagine you are approaching the bank. The wind ahead looks weak beneath the trees, while the centre of the river has more pressure.
A starboard boat approaches.
Ducking would allow you to continue, but towards somewhere you no longer want to go. A timely tack could take you towards the better wind instead.
Here, tacking combines traffic management with a useful change of direction.
Before committing, picture the position after the tack. Will you emerge with clear air and room to accelerate, or directly underneath another boat’s sails?
A tack that resolves the crossing but leaves you trapped in disturbed wind can carry a continuing cost.
Why Champagne Makes This Decision Interesting
Sailing an A-Rater on the Thames makes it difficult to separate boat handling from tactics.
With Champagne’s long hull and large sail plan, I want to think beyond whether there is just enough space to get through.
The more useful questions are:
Can we make the manoeuvre smoothly?
Will we retain enough speed?
Where will we emerge?
What happens at the bank or bend ahead?
Will we immediately need another manoeuvre?
That is one of the aspects of river racing I find most interesting. A small area of water can contain several different tactical problems at once.
There may be stronger wind farther across, less adverse current nearer one bank, and a substantial wind shadow behind another boat. The crossing sits inside that larger picture.
Champagne also makes a useful reminder that boat lengths are not interchangeable units across a mixed fleet. A gap that looks generous from one cockpit may feel very different from another.
Current Can Change the Value of the Manoeuvre
On a river, the direction your bow points and your movement over the ground are different things.
For boats close together in similar current, their relative motion remains central to judging the crossing. But the bank, moorings and marks are fixed to the ground, and current can vary across the reach.
That matters when choosing where to go afterwards.
For example, while racing upstream, a shallow duck might allow you to remain in a useful lane of weaker adverse current. Tacking away could send you towards a faster stream in the middle.
In another situation, the bank offers less current but so little wind that staying there is costly.
The question is therefore broader than “Which manoeuvre loses less distance?”
Which manoeuvre leaves us making better progress over the next minute?
When You Are the Starboard Boat
The crossing looks different when you have right of way.
You may wish to continue on your existing tack and let the other boat resolve the situation. You may also have tactical reasons to change direction, within the rules.
Either way, give the situation your attention.
A clear “Starboard!” can alert a crew who have not seen you. It should be communication, rather than an invitation to turn a manageable crossing into an argument.
Watch what the port boat is actually doing. Be ready to avoid contact if the situation deteriorates.
A shouted “Go ahead” is also a poor substitute for a sound crossing judgement. Do not assume that an informal exchange settles every rules consequence or accounts for other nearby boats.
For club racing, calm and predictable handling helps everyone make better decisions.
Do Not Let One Crossing Take Over the Race
One of the easiest tactical mistakes is becoming determined to beat the boat directly in front of you.
You tack to avoid passing behind. Then tack again to escape her disturbed air. Then defend a position that takes you away from the stronger wind.
Meanwhile, several boats elsewhere make steady progress.
The original crossing has consumed your attention and dismantled your plan.
A useful question is:
“If this boat were not here, where would I want to sail?”
Then ask which safe, legal option gets you closest to that intention.
Sometimes the answer will be to cross ahead. Sometimes it will be to tack. Quite often, it will be to accept a modest duck and carry on.
A Simple Crossing Checklist
As the boats converge, work through five questions:
Who must keep clear?
Can we cross with a comfortable margin?
Where do we want to sail next?
What lies beyond the tack or duck?
Can we act now, smoothly and clearly?
The final question matters enormously.
A modest manoeuvre made early usually leaves more options than a desperate manoeuvre made late.
Practise the Decision as Well as the Manoeuvre
With another willing crew, practise crossings in open water with generous separation.
Begin with comfortable ducks and well-spaced tacks. Gradually explore how speed, angle and timing affect the outcome.
After each attempt, discuss:
When did we first identify the crossing?
Was our intention clear?
How much speed did we retain?
Did we emerge where we wanted?
Would the same choice have helped during a race?
Use the exercise to improve judgement and coordination. Close margins are unnecessary.
Conclusion: Think Beyond the Other Boat’s Stern
Crossing another boat is a small moment with consequences that can last much longer.
The apparently bold choice may cost two tacks. The apparently cautious choice may preserve speed, clear a traffic problem and keep you sailing towards the best wind.
On the Thames, aboard Champagne, that wider view matters. Trees, bends, current and the next approaching boat all remain part of the decision.
Know your obligations. Look early. Leave a sensible margin. Then choose the manoeuvre that supports the next part of your race.
Sometimes the quickest way ahead is to go behind.




