The racing rules are written in defined terms. Learn what keep clear, overlap, room and zone mean, and the right-of-way rules become short.
1 · Tack, leeward, windward
Which side the wind is on
On a run with my boom to port, am I on starboard or port tack?
Starboard tack: your tack is named after your windward side, and on a run that is the side opposite your mainsail. The tack changes only when you pass head to wind or the mainsail crosses.
Your leeward side is the side away from the wind. Head to wind, it is the side that was leeward before; dead downwind or by the lee, the side your mainsail lies on. The other side is windward, and it names your tack: starboard or port.
So the tack changes only when you pass head to wind or, on a run, when the mainsail crosses. Of two overlapped boats on one tack, the one to leeward of the other is the leeward boat.
Rule
Boom to port on a run: starboard tack.
2 · Clear astern, overlap
Behind you or alongside you
When are two racing boats overlapped, and does a bowsprit count?
Two boats overlap when neither is clear astern of the other, entirely behind a line abeam from her aftermost point of hull and equipment. Equipment counts, such as a rudder or a bowsprit set with its sail; distance does not matter.
Take a line abeam from the aftermost point of your hull and equipment in normal position. A boat entirely behind it is clear astern; if neither boat is clear astern of the other, you overlap. Equipment counts: a rudder, a bowsprit set with its sail.
Distance does not matter, and two boats also overlap when one between them overlaps both. On opposite tacks the terms apply only when both boats sail more than 90° from the true wind or when rule 18 applies between them; on a beat, rule 10 alone decides.
3 · Keep clear, room, proper course
Three yardsticks
Does keep clear in the racing rules mean keeping a set distance away?
No: you keep clear when the right-of-way boat can sail her course with no need to take avoiding action and, if you are overlapped, can change course either way without immediate contact. Distance and hails are not the test.
You keep clear when the right-of-way boat can sail her course with no need to take avoiding action and, if you are overlapped, can also change course either way without immediate contact. The test is her need to act, not distance or a hail.
Not keeping clearstarboard has to luff
Not keeping clearleeward cannot luff without contact
Room is the space a boat needs in the existing conditions to manoeuvre promptly in a seamanlike way, including space to meet her obligations under Part 2 and rule 31.
Proper course is the course you would sail to finish soonest in the absence of the other boat the rule refers to. It shifts with the wind, and before your starting signal you have none.
4 · Mark, zone, mark-room
The words of a rounding
How big is the zone around a racing mark, and when am I in it?
The zone reaches three hull lengths of the boat nearer the mark, and you are in it once any part of your hull is. Each gate mark has its own zone.
A mark is an object the sailing instructions require you to leave on a stated side, or a committee vessel from which the starting or finishing line extends. A fender hung on it is part of it; its anchor line is not.
The zone reaches three hull lengths of the boat nearer the mark. You are in it once any part of your hull is. Each gate mark has its own.
Mark-room is room to sail to the mark, round it on the required side and leave it astern: a seamanlike rounding, and room, not right of way. Since 2025 it has no separate clause on tacking. A boat fetching the mark will pass to windward of it without another tack.
5 · Obstruction
What you cannot simply sail past
Is another racing boat an obstruction under the racing rules?
Only to boats that must keep clear of her or, under rule 22, avoid her. An obstruction is an object you could not pass without changing course substantially if you sailed straight at it from one hull length away.
An obstruction is an object you could not pass without changing course substantially if you sailed straight at it from one hull length away, or an area the event's rules close to boats. A boat racing is one only to boats that must keep clear of her or, under rule 22, avoid her.
Obstructionone length away, straight at it
Continuing obstructionthree lengths or more along it
A continuing obstruction is one the boats pass along for at least three hull lengths; a vessel under way never is, nor a committee vessel that is also a mark. A small buoy is a mark without being an obstruction.
6 · Racing, start, finish
When the race begins and ends
When does a boat start racing under the rules, and when does it stop?
You are racing from your preparatory signal until you finish and clear the line and marks, retire, or a general recall, postponement or abandonment is signalled.
You are racing from your preparatory signal until you finish and clear the line and marks, retire, or a general recall, postponement or abandonment is signalled.
You start when, your hull having been entirely on the pre-start side at or after the starting signal, any part of it crosses the line. You finish when any part of your hull crosses the finishing line from the course side, unless you then take a penalty, correct an error in sailing the course or sail on.
To sail the course, your track drawn taut must pass each mark on its required side and each gate from the previous mark's direction. A mark that does not begin, bound or end your leg has no required side.
Signal
The race is
Postponed · AP
Delayed; may be started or abandoned later
Abandoned · N
Void; may be resailed
7 · Principles, rules 1–4
What you agree to by racing
Do I have to take a penalty if nobody protests me?
Yes: under the Basic Principles, a boat that breaks a rule and is not exonerated promptly takes a penalty, which may be to retire, whether or not anyone protests.
The basic principle: break a rule without being exonerated and you promptly take a penalty, perhaps retiring, whether or not anyone protests.
Rule
What it asks
1.1
Help anyone in danger, racing or not; redress for places lost
1.2
Your flotation is your own responsibility
2
Fair sailing: a deliberate breach means a non-discardable disqualification
3
The decision to race is the boat's alone
4
Accept the rules and appeals; no courts
A rule includes the notice of race, sailing instructions and class rules, not club customs or the Basic Principles. A protest is an allegation under rule 60 that a boat broke a rule; the hail only announces it. Its parties are protestor and protestee, never witnesses or the protest committee.
Practice questions
Questions from this topic, as the app asks them. Open one to see the answer.
Both you and Blue are close-hauled on starboard tack and overlapped. Looking forward, Blue is on your left, on the side away from the wind. Which of you is the leeward boat, and who keeps clear?
Blue is the leeward boat — she is on your leeward side — and you, the windward boat, keep clear under rule 11
You are the leeward boat because you are nearer the wind, so Blue keeps clear
Neither — the terms windward and leeward are used only on a run
Blue is the windward boat because she is slightly ahead of you
Show the answer
A. Blue is the leeward boat — she is on your leeward side — and you, the windward boat, keep clear under rule 11
Definition Leeward and Windward: when overlapped on the same tack, the boat on the other's leeward side is the leeward boat; rule 11.
Wednesday evening club race, J/24s on a starboard-tack reach. Red is directly behind you; her bow is about a metre behind the line abeam of your transom. In the words of the rules, are you overlapped?
No — Red is clear astern: her hull and equipment are behind a line abeam from the aftermost point of your hull
No — boats are overlapped only when they are side by side with their bows level
Yes — an overlap exists whenever two boats on the same tack are within hailing distance
Yes — boats on the same tack within two hull lengths of each other are always overlapped
Show the answer
A. No — Red is clear astern: her hull and equipment are behind a line abeam from the aftermost point of your hull
Definition Clear Astern and Clear Ahead; Overlap: a boat is clear astern when her hull and equipment are behind a line abeam from the other's aftermost point.
You are close-hauled on starboard tack. Blue, on port tack, tries to cross ahead but misjudges it: to avoid hitting her you have to luff about 20°. There is no contact. Did Blue keep clear of you?
No — you could not sail your course without taking avoiding action, so she failed to keep clear
Yes — there was no contact, which is all that keeping clear requires
Yes — a port-tack boat is allowed to cross within one hull length if she can
Yes — you chose to luff; a boat keeps clear as long as she does not actually hit the other
Show the answer
A. No — you could not sail your course without taking avoiding action, so she failed to keep clear
Definition Keep Clear: the right-of-way boat must be able to sail her course with no need to take avoiding action — she had to luff.
You are sailing an ILCA 7 (hull 4.2 m) towards the windward mark with another ILCA close by. How far from the mark does the zone begin for the two of you?
About 8.4 m — two hull lengths
About 16.8 m — four hull lengths
A fixed 20 m round every mark, whatever the boat
About 12.6 m — three hull lengths of the boat nearer the mark
Show the answer
D. About 12.6 m — three hull lengths of the boat nearer the mark
Definition Zone: the area around a mark within a distance of three hull lengths of the boat nearer to it.
You and Blue are overlapped on port tack, you to leeward. Grey, on starboard, will cross close ahead of both of you. Blue says a boat racing can't be an obstruction. Is Grey an obstruction to you and Blue?
No — a boat racing is never an obstruction, only moored vessels and land are
Yes — a boat racing is an obstruction to boats that must keep clear of her, and both of you must keep clear of Grey under rule 10
No — Grey is an obstruction only to the boat nearer to her
Only if Grey is more than twice your hull length
Show the answer
B. Yes — a boat racing is an obstruction to boats that must keep clear of her, and both of you must keep clear of Grey under rule 10
Definition Obstruction: a boat racing is an obstruction to other boats only if they are required to keep clear of her (or avoid her under rule 22).
Your bow crosses the finishing line from the course side, the committee sounds a horn, and your crew asks whether you have to sail the whole hull across before you have finished. Have you finished?
No — a boat finishes only when her whole hull has crossed the line
Yes — you finished when any part of your hull crossed the line from the course side; you need not cross it completely
No — a boat finishes when her mast crosses the line
Only once the race committee records your sail number
Show the answer
B. Yes — you finished when any part of your hull crossed the line from the course side; you need not cross it completely
Definition Finish: a boat finishes when any part of her hull crosses the finishing line from the course side; she need not cross completely.
All 100 questions of this topic are in the app: practice by topic with the reason after every answer, your mistakes brought back, and a timed mock exam. Free, no sign-up, in the browser or in Telegram.
