Yes, there are conflicting thoughts about RF grounds. Those of us who've been experimenting with them -- both on boats and ashore -- for several decades, and who have used them and written about them extensively, have some pretty strong ideas about what works and what doesn't. Also, we have some clues as to WHY this is true.
I did a piece entitled "RF Grounds in the Marine Environment" on the SSCA Board some years ago. It was repeated elsewhere, but I'm sure you can find it on the Board.
Bottom line: lots of things work, some easy to install, some not so easy. Since I do SSB installations for a living these days, I've got a repetoire of possible solutions, depending on the boat, the circumstances (intended use), and the owner.
In a recent presentation for SSCA I enumerated some of the things which work well:
- Copper strap to bronze thru-hull near tuner
- Aluminum toerails (with sections linked together)
- S/S rubrails (sections linked together)
- Rudder and autopilot s/s framing complex
- S/S radar and solar panel arch
- S/S lifelines and pushpit/pulpit complex
- Radials (wires or copper strips), tuned or untuned
- Metal hull to deck beam
- Large aluminum swim platform
- Metal hull
If you want to go to the trouble of moulding wire mesh into the hull at layup time, or mounting bronze plates, etc.....those will work, too. But, they're unnecessary and overkill.
What is NOT a good idea is tying the RF ground to the boat's DC ground system, including the engine and/or any of it's component parts. The RF ground should be separate from other onboard grounding systems.
Do radials work? You betcha. Try it yourself. Hoist a random length of wire, over 23' long with a spare halyard. Affix it's lower end to the tuner antenna lug. Now, throw a 1/4 wavelength piece of insulated wire along your side deck, with one end attached to the tuner ground lug. For the 8mHz marine band, you'd need a wire (any kind) about 234/8 = 29.25' long.
This simple setup will tune very well on the 8mHz marine band, and will put out a pretty decent signal. Hams do this all the time. So do broadcast stations (which often use elevated radials). No need to have contact with seawater or even "couple to seawater".
Notice we're talking WIRES here for radials. But you'll find in just about every marine SSB book and in many instruction manuals statements to the effect that "wires don't work; you've got to use wide copper strips for radials". Balderdash. And, just one of the many myths and downright WRONG statements found in places where the authors are just parroting what they've read or heard elsewhere.
Lotsa ways to skin a cat. Read the ham stuff, experiment yourself, and talk to hams and marine professionals who've been there.