One interesting part of the rule is that there is no requirement as to when the flag and sound signal must be made. It only needs to be made in enough time that the first boat approaching the new finish mark (in our example above, the “old” Mark 1), sees and hears the signal to finish.
This is another frequent point of confusion and misunderstanding for many racing sailors. As we will see later with RRS 33 (Changing the Net Leg of the Course), those signals are made prior to boats sailing the leg. That is not the case with Rule 32 – and, in fact, it is for a very good reason.
If the shortening signal (eliminating a leg) was required to be signaled earlier, it may be too soon or not soon enough – think of the reasons to shorten… foul weather, insufficient wind, safety & fairness, etc. These are not things that can always be anticipated. Doing so might result in the signal being made unnecessarily (conditions improve) or, worse yet, leaving the race committee with only one option – abandonment – in the case of severe weather & safety.
Often, when considering shortening, the race committee will get everything ready, just in case, and the PRO will make the call at the last minute and direct the mark boat to hoist the flag with two sounds as the first boat is nearing the mark. How near? Close enough to see and hear the signals, yet not too close for it to be effective. Like many things with course management, it depends.