On Aug 27, 12:12 am, "Armond Perretta"
wrote:
....
As Lew has indicated, the reason that running machinery, even out of
gear, is considered "under power" is that there is no reliable way for an
observer to determine the crossing rules that apply. ...

While I think your conclusions are probably right, I just hate the
argument you are making here. I can't think of a single instance
where it would be possible for an outside observer to distinguish
between a sail boat with propulsive machinery running but not engaged
in propulsion and a sail boat with non-propulsive machinery
running... Prudence requires the observer to assume that a boat that
looks like it is under sail including its lights and shapes is under
sail even if it is belching smoke and water.

-- Tom.