Nick Martin » Double Tack

The Hamster's question has been brought up before regarding gaining from the multiple tacks, particularly when the boat does not actually complete its "first" tack. If the breeze was particularly lighter than in the video and the boat never completed its "first" tack and rolled into the next and gained, then that may violate rule 42.

I emphasize "first" because the boat is still in the process of completing its tack until it reaches a close hauled course.
I am not sure that there is a clear definition on tactical considerations for it. Unless the boat is doing the manouver just for the sake of gaining through propulsion, I would think that this is completely legit.
This is typically a very downspeed manouver to go tack for tack with the opponent or to make a mark and not one where gaining from it is very likely.

How legal is that? - okay from these shots it is not easy to tell if "after the tack speed is not greater than it would have been in the absence of the tacks" (42.3b) but it is clear that the "boats crew are using their bodies to exaggerate rolling" NOT "to facilitate steering" (42.3a) as they are rolling the wrong way for that! But rather are "moving their bodies to propel the boat" (42.1)!

Similarly - is there any clarity or definition of the "tactical considerations" that would make such repeated tacks acceptable without falling foul of 42.2(c)?