You are all making a song and dance about it.

Whatever the ground electrode system happens to be, the impedance to
Earth cannot possibly be less than the series impedance of the
connecting lead. Which can be quite high at HF.

In my opinion, the most effective ground will always be a short,
thick, direct connection from the radio equipment to the internal hull
of a metal boat.

If you like, you can connect whatever else you have in mind in
parallel with it, probably at the other end of a long lead, and it
won't make the slightest improvement in performance.

Just use your loafs. And Happy sailing!
----
Reg, G4FGQ.