I agree to the phrase " the moment it would be clear to a competent, but not expert, sailor at the
helm " as the key variable.

In a close quarter situation, however, there are many other variables like the boat- size, shape, rudder effectiveness etc, then the environment-wind speed, steady or gusts, waves, swell, visibility etc and last but not the least the level of competition- it sets a bar for the competence of the crew expected.

The answer lies in interpretation of the situation based on the evidence by the parties and the jury's application of their perception of the environment (this may not be written anywhere but practically always boils down to the perception of each member of the panel. The perception is dependent on so many variables, that itself can be a separate topic of discussion)

The WASZP rule 42 guidelines are interesting, but seem to be pretty difficult to enforce; I do believe that it is the class prerogative to determine the best way to address rule 42 for these kinds of boats.  In general, the answer is probably to not hold events for foiling classes in non-foiling conditions; sailors on foiling boats generally don't want to race if they aren't on foil anyway.  For the wingfoils specifically, pumping includes the foil and the sail together, and is a generally accepted practice as written in Appendix WS.

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.

To me once a boat had done a 44.2 set of turns, they have not initially finished and there can be no other score but the last finish.

Other rule breaches are something else which really should be protested by boats.

There is no reason for a rc to act if they score the finish after the turns.

John,

Very interesting question. To shed some light on the question of whether someone goes faster by flattening the boat than "otherwise", here's a video of an ILCA acceleration with actual speeds in the top right. I'd suggest on focusing on the footage from 02:10 to 02:30. (I'm the guy in the video.)

Here are my observations of this video:

Without the speed chart, I could see you claim (in good faith!) that at 02:14, I'm committing a prohibited ROCK 4 to propel (accelerate) the boat faster. But in fact, the boat slows.

Meanwhile, the "single action of the body that clearly propels the boat" is hiking parallel to the water. I doubt anyone here would claim that hiking hard would be considered a ROCK 4, but the data show it's propelling (accelerating) the boat.

Curious to hear your thoughts.

Addendum: in case anyone's curious about the data source, it's a GoPro Hero 13 Black, with GPS position sampling at 10 Hertz (10 latitude/longitude readings per second).