Can you expand on this?

Thank you all for your comments.  Yes, my question was meant to boil down to "what is reasonable?" and "reasonable to whom?"  Yes, I was quoting Case 50.

I wrote the facts to try to convey that S was too far out for P to know whether S had luffed to slow or, alternatively that the boats had changed relative speed for some other natural reason. 

As a low-level racer, really what I'm looking for is an understanding of any  rules of thumb or helpful conventionalities available to all boats. So your discussion of times and distances is helpful.

I'm still a little unclear on what, exactly, it means to hail "starboard".  Is it:  (a) Do you see me?  or is it (b) I feel the need to change course, so if you don't tack/duck immediately, you will have broken the rules.  I guess (b)?

Really really what I'm looking for is a way to decide whether/when my P-boat conscience can be clear after S-boat changes course when at a longish distance out.

Thanks.

John, I am glad that the WASZP rules are working in practice.  I think that the wingfoils will go a different direction, with little or no limitations, at least in part because they are always in the standing position.  I think that should be up to the fleet decide and adopt in their class rules so we shall see as the class matures.

I'm with Phillip, in the definition its a measure, and that measure should be consistent. A less than competent crew is not entitled to more room than an expert one, and would be breaking a rule if they require it (lets leave room made freely available out of it for now).  Similarlty an expert crew is allowed the same room as a competent one, even though they may not need it,

John, I agree with you about reasonable apprehension and skill level, but I think its a red herring in the context of Room and Case 103.

The world sailing judges manual changes on improper act or ommission in each version, each seeming giving judges more room for interpretation. Just track the change next time, it may be what gordon and i may expect.
The old bad race management hidden behind the word may not shall,, may not be tolerated.
A time of change perhaps! I believe for the better if we are to improve standards and improve the sport.