Ellen MacArthur wrote:
Capt. JG said he sailed backwards for an hour. If another sailboat was sailing directly
toward JGs transom would it be an overtaking situation? And would the other sailboat have
to give way. How would it know if JG was sailing backwards or just very slow forward.


You seem to still be uncertain about how current should be considered.
In Jon's case, he was making way through the water forward, but the
current was pulling him (and your other hypothetical boat) back. From
the perspective of the two boats, this is a simple overtaking
situation - the boat moving through the water faster is overtaking
Jon. Even though its possible that they are going in opposite
directions over the bottom, this is not a head-on meeting situation.
(And, as sailboats, that rule isn't used, what rule would apply?)

The case I described was rather different: I was pointed into the wind
while holding the boom tight to the mast, making several knots
sternway and keeping fair control with the rudder. In fact I've done
this many times, and we would have races where the downwind legs were
to be sailed backwards.

This raises the question that also comes up when large ship are
maneuvering in a harbor. When you're making sternway, do the rules
get reversed? For large ships, the common practice is make passing
signals assuming your stern is now the bow, and this has been upheld
in the courts. However, this it is also "special circumstances"
because maneuverability is greatly reduced.

But, for a small sailboat doing this, how do you tell which tack
you're on?