Gary-
The ideas that you are advancing may work...however they absolutely fly in
the face of all conventional wisdom wrt installing an end fed antenna system
on a non-steel boat using a modern antenna coupler/tuner. I have not
personally tried what you are proposing, but I have personally installed
many dozens of systems using the more conventional methods that are reported
in the literature and...these methods work...5 by 9 reports first crack out
of the box.

Do not misunderstand me, I am simply stating that installing the
coupler/tuner as close as possible to the feed point of either a shipboard
vertical or an insulated backstay, when the other half of the system is a
modest counterpoise, yields very satisfactory results.

Do you have any actual results from a system where the coupler/tuner where
positioned close to the counterpoise? If you do, and you achieved good
signal reports, than maybe the actual position of a coupler/tuner is
irreverent.

73-
Charlie
KS4VB