AP over A implies that you may start a race on another day for this regatta, so I do not feel that it is technically correct unless the regatta has a provision to be rescheduled or the time limit can be extended for more races.

N over A seems more correct since you are abandoning the day's scheduled races and thereby concluding the regatta.

Alternatively you could use N over H because it does the same as N over A, but instructs competitors to return to shore for more information, so, being the last day of the regatta, you can hoist "L" and give prizes when ready.

Of course it's all just semantics since the competitors will all know what you mean no mater which of the two you choose, but tossing in the "H" is almost guaranteed to confuse them.

AP over A is the correct flag if no race has started.  The text is "Races no started are postponed, No more racing today".  If there is a race in-progress, then N over A.

If "time limit is over", neither of them. The time limit for a start, once is over, it is the signal for not more races by itself.

My view would be N over A.  In this context we are not postponing anything - there is no intention to run any more races therefore we are abandoning.  Unfortunately had to do this yestarday as sat for six hours waiting for breeze and when last time to start a race arrived displayed N over A.  However if it was on the first day of a two day event then I would use AP over A. Which is also what I had to do this weekend - first time I lost a complete two day series in twenty five years! 

The N flag is to abandon a race that is in progress.  Having H or A under it means stop racing and go to shore where you might either race or not again that day.  Since no race is running, N is inapprorpriate.  I still believe the AP flag should be on top of A is the appropriate flag.  Simply pulling anchor and going home with no flag and no sound signal when the time limit is reached does not seem approriate to me IF there are boats that can see the RC.

I'm going to go with N over A. Although N says "All races that have started are abandoned...", the phrase "that have started" is not included in the description of N over H or N over A.
Use of AP implies that they will be started at some future time, which is not the case here.

Therefore, N is preferred (at least by me).

Bruce;

I agree that "N" alone is to abandon a race in progress (that has started), however when used with other signals it may relate to races that have not yet started per the last sentence of the signal "N", "...unless at that time the race is abandoned again...".  Therefore you can abandon a race that has not started with N over H or N over A.

The alternative, once the time limit is up, is to put up "L" and motor back to the harbor with no other signal.  However, we are in the customer service business as race officers, so what is most likely to be universally understood by the competitors?  I would say N over A is most correct, but AP over A is frequently used in my experience and is equally understood by the competitors.

I agree with Clark in that that "AP implies that they will be started at some future time" but with the H or A under AP, you then know whether to wait on shore [where an AP may also be flying that could come down later that day or have an N raised under it with two horns].  If there is no race in-progress then there is nothing to abandon so N should not be flown.  The crux is to postpone not abandon.

If there is "no race in-progress" you certainly can abandon races that have not yet started.  You just don't do it with N alone.  See RRS 27.3.  You are abandoning additional races that were scheduled for that day of the event with N over A or H.  

If it is the last day of the event the RC is abandoning races scheduled (by the SI), that have not yet started, and ending the regatta without starting all scheduled races by using N over A.

Additonally, per your statement "[where an AP may also be flying that could come down later that day or have an N raised under it with two horns]", there is no such signal as "AP over N".

But...
if you fly N over A, you abandon races and no more races today. That's the meaning of the flags. Anyway you are saying that no more races are going to be sailed today because you abandoned them but happens the same that with AP. the meaning of A says that today the day is done, but doesn't talk about tomorrow or any other day. So abandon or pospon is only today in any case.

so...
is any signal over the other?

Once the time limit is over, you have no races to abandone or pospone, so there is no signal to abandone or postpone a race that does not exist.
Just go back to shore with no signals hoisted.
 

As a race management instructor, I teach my students, "You can't postpone a race that's underway and you can't abandon a race that hasn't started."  That works about 95% of the time and this is one of those times where it doesn't.  If absolutely no more races will be held, then November over Alpha is appropriate ("All races are abandoned. No more racing today").

Definition of Postpone - A postponed race is delayed before its scheduled start but may be started or abandoned later.
Definition of Abandon -  A race that a race committee or protest committee abandons is void but may be resailed.

I caution my students that either AP over A or N over A is the "nuclear option".  Once displayed, you're done for the day.  There's no "un-ringing" the bell if the wind fills in. 

And if the "drop dead" time limit (on the last day, no races started after . . ) has been exceeded, then you drop AP one minute before, then put up N over A.  Everybody understands that and heads to the bar (if they weren't half way there already).

It comes down to the First Commandment of Race Management ("Thou Shalt Not Confuse the Competitors") - if the competitors understand what's going on, then it really doesn't matter what's flying on the flagpole.

A correction to my comment on "[where an AP may also be flying that could come down later that day or have an N raised under it with two horns]",  I should have said asshore AP over A could be flow so everone knows no more races that day.  Anyway that's besides the point.  I'm still in the lonely party of 1 in thinking AP over A is the correct flags not N over A.

In this senario no race is in-progress so the RC is postponing not abandoning because Postpone is defined as "A postponed race is delayed before its scheduled start but may be started or abandoned later.".  Abandon is defined as "A race that a race committee or protest committee abandons is void but may be resailed." means to me that a race is in-progress, and that is only when N should be raised.  The N tells boats to stop racing.  The AP tells the sailboats the start is delayed with the added A meaning delayed for an other day or if the last day of the regatta, no more races at all.

Yep. Sound two hoots, drop the orange and yank the chain. No one is looking for flags at that point.

Dear Folks:
"A" goes for afterwards. "H" goes for home.
I think the proper signal is N (abandoned) over H (go home).

If you arrive at the time limit on the final day with no wind then more than likely you will already be flying the AP. In any event the scheduled start time of the next race will already be past as you can't schedule the start of a race for after the time limit. Race signals state that AP over A means "races not started are Postponed no more racing today". The definition of Postponed says that the race is delayed before it's scheduled start time but may be abandoned later.

To my mind by the time you reach the time limit you are well past the "delayed before it's scheduled start" part of the definition and well into the "abandoned later". the signal to abandon a race with no more racing today is N over A.

Mr. Matt Bounds
Refering to your first paragraph ("you can't abandon a race that hasn't started") I suggest to read the wording of rule 30.4 RRS.

Mr. Soneyra - I am quite familiar with the wording of 30.4.  The saying is merely a mnemonic to help inexperienced race officers know the difference of when to postpone vs. abandon.  I also mentioned that it is applicable only about 95% of the time.

I will wager that the vast majority of race officers have never abandoned a black flag starting sequence before the start - they will AP rather than abandon.  If you abandon a black flag starting sequence at the last second before the start - will the competitors know that you did it before or after the starting signal?  If you postpone, there is no doubt.

No Confundas a los Competidores.

In the scenario that Cesar mentioned, I had that exact same scenario at the recent Optimist Worlds in Thailand. Last day of the event - sadly not enough wind to run racing that day. Time limit for the Warning signals expired.
We displayed N over A to return the fleet back to shore - end of racing that day and end of the regatta - no opportunity to resail.