>>> We want to mount a transponder antenna in the belly of our LIV.
Does the carbon fiber provide an adaquate ground plane?
With the conductive paint option I was concerned about flexing,
especially in the pressure vessel areas, creating micro cracks over
time.  I mounted a thin (.021) sheet of solid copper from McMaster-Carr for the
ground plane  <<<

Barry,  I used a non-woven metalized graphite fibre cloth.  It bonds on to the
graphite composite easily and follows complex curves.  I had used it on
EMI/RFI shielding studies years ago and found it to be quite effective.
The company is working on military applications and had approached
Columbia regarding its use as a lightning protection.  Nice folks to
deal with but they are across the pond.  My contact from 5 years ago is
Mike Devoe: mike.devoe@techfibres.com.  Robert M. Simon
ES-P N301ES