Ed G wrote:

...
Ed

Oh yeah, Richard is quite correct there--don't choke off the
counterpoise--but, I bet you already suspected that ... and, don't use
the coax as a counterpoise! Well, unless you design for that ... but
then, don't run the counterpoise in the inside of the vehicle ... well,
your vehicle is fiberglass, kinda hard to hide from the
antenna/counterpoise, but again, you already knew that ...

Regards,
JS