A race committee talks to the fleet almost entirely in flags. The flag carries the meaning, the sound signal only tells you to look up, and if you miss the flag you have missed the instruction. This is the full set, grouped the way you actually meet them on the water rather than in alphabetical order.
One principle sits under all of it. A sound signal never carries information by itself. It draws attention to a visual signal, and the visual signal is the one that counts. When the two disagree, the flag wins, and a missing or late sound signal is not grounds for redress on its own.
The start sequence: P, I, Z, U and the black flag
The preparatory flag goes up four minutes before the start and comes down one minute before it. Which flag the committee chooses tells you what happens to a boat that is over early.
- P is the plain preparatory signal. A boat over the line in the last minute simply returns and restarts.
- I signals that rule 30.1 applies. A boat on the course side in the final minute must sail to the pre-start side around either end of the line before starting. This is the round-the-ends rule.
- Z signals that rule 30.2 applies. A boat in the triangle formed by the line ends and the first mark during the final minute takes a scoring penalty without a hearing.
- U signals that rule 30.3 applies. A boat in that same triangle in the final minute is disqualified, but not if the race is restarted or resailed.
- Black flag signals that rule 30.4 applies. Same triangle, same final minute, and the disqualification stands even if the race is restarted or resailed. This is the strongest deterrent the committee has and it is the one that most often ends up in the protest room.
The escalation from P through to the black flag is a race management decision, not a rule. In our experience the black flag comes out one general recall too late more often than one too early. If you are running a big one design fleet on a short line, going straight from P to U after the first general recall is usually the calmer outcome.
If you are new to running a start, the mechanics of the sequence itself are worth reading alongside this chart: our guide to mastering the start sequence in junior race officer training walks through the timing rather than the flags.
Recalls: X and First Substitute
X is the individual recall. One or more identified boats were on the course side at their starting signal, or broke rule 30.1. The flag goes up immediately with one sound signal and stays up until every one of those boats has fully returned, or for four minutes, whichever is sooner.
First Substitute is the general recall. Two sound signals go with it. The whole fleet comes back and the warning signal for a new start is made one minute after the flag is lowered.
The practical difference matters. X is a signal to a handful of boats and the race continues. First Substitute stops everything. A committee that flies X when it cannot actually identify the boats has created a problem it will not be able to defend later, so if you are not certain who was over, the honest signal is First Substitute.
Postponement: the AP family
AP on its own means races not started are postponed. The warning signal follows one minute after AP is lowered, unless at that moment the race is postponed again or abandoned.
AP over H means races not started are postponed and further signals will be made ashore. Go in.
AP over A means races not started are postponed and there is no more racing today.
AP over a numeral 1 to 9 means the postponement runs that many hours from the scheduled starting time.
The numeral pennants are the most underused signal in the set. A fleet that knows it has three hours is a fleet that eats lunch and stays calm. A fleet under a bare AP with no information starts inventing rumours within twenty minutes.
Abandonment: the N family and V
N means all races in progress are abandoned. Return to the starting area. The warning signal comes one minute after N is lowered unless the race is abandoned again or postponed at that moment.
N over H means all races in progress are abandoned and further signals will be made ashore.
N over A means all races in progress are abandoned and there is no more racing today.
V means monitor the communication channel for safety instructions. V is not an abandonment signal and it is not a distress signal. It tells the fleet that the committee is about to say something on the radio that matters, which in practice usually means conditions are changing faster than flags can keep up with.
Deciding when to abandon is the hardest call a race officer makes, and it is far easier to defend when it rests on a measured number rather than a feeling. We have written separately about what wind speed is too high for a sailing race and the reasoning behind the decision.
Changing the course while racing: C and S
C means the position of the next mark has been changed. It never travels alone. A green triangle or the numeral pennant arrangement showing green means the change is to starboard, a red rectangle or red means to port, a minus sign means the leg is shorter, a plus sign means it is longer.
S means the course has been shortened and rule 32.2 is in effect. The finishing line is then formed at the mark, in the way that rule describes.
Both are made from a vessel at the mark, and both need the fleet to see them in time to act. A course change flown late is worse than no course change at all.
The rest of the set
L ashore means a notice to competitors has been posted. Afloat it means come within hail, or follow this vessel.
M means the object displaying it replaces a missing mark.
Y means wear a personal flotation device. This one is a rule, not advice, and the penalty for ignoring it is a disqualification without a hearing under rule 40.
Orange flag marks one end of the starting line.
Blue flag marks one end of the finishing line, when displayed by the committee boat.
The sound side of the system
Flags are only half the instruction. If nobody looks up, the flag has not been made. A committee boat needs a sound signal that carries across a fleet in twenty knots of breeze and against a sea state, which is more than most handheld devices manage.
This is one of the few pieces of committee boat kit where the cheap option is genuinely a false economy. A handheld metal fog horn built from polished metal, with a cap that protects the reed and no gas canister to run out mid-sequence, is the difference between a clean start and a general recall caused by nothing but a fleet that did not hear the preparatory signal.
Frequently asked questions
What does the AP flag mean in sailing?
AP means races not started are postponed. The warning signal is made one minute after AP comes down, unless the race is postponed again or abandoned at that moment. AP over H sends you ashore, AP over A ends racing for the day, and AP over a numeral gives the length of the postponement in hours.
What is the difference between the X flag and First Substitute?
X is an individual recall for identified boats and the race carries on. First Substitute is a general recall, made with two sounds, that stops the whole fleet and restarts the sequence.
What does the black flag mean at a sailing start?
It signals that rule 30.4 applies. A boat inside the triangle formed by the line ends and the first mark during the last minute before the start is disqualified, and that disqualification stands even if the race is restarted or resailed.
Does a missing sound signal invalidate the flag?
No. The visual signal governs. The sound signal exists to draw attention to it, and an absent or mistimed sound does not by itself change what the flag means or entitle a boat to redress.
What does the Y flag mean?
Wear a personal flotation device. It is enforceable under rule 40, and a boat that ignores it can be penalised without a hearing.
Where to go from here
Print this chart, laminate it and keep it in the committee boat folder. The flags themselves are only useful if the rest of the boat is set up to fly them on time, which comes down to a hoist you can reach, a timer you trust and a sound signal the fleet can hear. Our race officer kits are built around that sequence rather than around a shopping list.