Most of our antennas have some kind of counterpoise---a ground plane,
radials, etc. This is for the rf in the radiating part to "push" off of.

A question is how the common fiberglass marine VHF antennas work. In many
installations, there is no visible counterpoise.

So, how do they manage to radiate? Maybe the coax outer shield forms a
counterpoise. Don't know. Just curious.