"RB" wrote in message
.. .
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.

These antennas are half-wave antennas and they don't need a counterpoise.
Only a quarter-wave antenna needs one, to account for the other missing
quarterwave part, so to speak.

Meindert