A question on rule 42: there's a type of heavy, full-keeled sailboat where it's possible to ease the vang downwind and induce continual rocking, even without any of the actions listed in 42.2b:

1) body movement
2) repeated adjustment of the sails
3) steering.

Is this action prohibited under Rule 42 or not?

Some background:

42.2 states, "Without limiting the application of rule 42.1, these actions are prohibited." (In other words, other actions could be prohibited even if not listed.)

The US Sailing rule 42 logbook states that the following are permitted (page 3):

ROCK 3: Background rolling is permitted. (Is the above action considered a ROCK 3?)

ROCK 4: Non-repeating unstable settings ok. The action above has the vang eased once on a downwind leg, i.e., it's non-repeating. (Is the above action considered a ROCK 4?)

Thanks!