In World-War-One J.H.Rogers invented and patented an antenna that worked well underground or underwater. It was used to communicate with Subs at the time.

According to the late, and somewhat controversial, T.E.Bearden the Rogers system has been rediscovered and then "lost" at least five times since WW1.

"James H. ROGERS Underground & Underwater Radio ( Static-free Reception & Transmission Underwater & Underground )"

https://www.rexresearch.com/rogers/1rogers.htm

There is also

Wallace MINTO Hydronic Radiation Transmitter

Radio-Electronics (May, 1967), p. 37-38.

“Build a Hydronic-Radiation Transmitter”

by Jack Althouse

“Scientists in Florida have discovered a new form of electromagnetic radiation which propagates under water as well as radio does in air”.

https://www.rexresearch.com/hydronics/hydronics.htm

While not indented for water use the Sutton & Spaniol et.al.'s "Black Hole" Antenna is always of interest when it comes to VLF/ELF. This work was done for NASA. Dr Sutton described it to me this way:

"Re: ACTIVE ANTENNA From: John and Helen Date: 10/02/05 10:54 pm

Hi Bob,

The synchronous detectors were used in temperature monitors and temperature controllers designed to control temperatures on spacecraft at 60 milliKelvin +/- a few ucroKelvin. The preamplifier had to have a gain of 10E5 after which the demodulated signal had to be converted by a 16 bit ADC, with +/- 1LSB allowable error.... so of course, you can see that we were working with extremely small signals buried in the noise, and we had to go all out in an effort to beat down the noise. That's why we had to use a new improved synchronous demodulator. This project was as close to being impossible as you can get! I still have trouble believing that we actually made it work.

The active ("Black Hole") antenna was developed in another project, where we didn't want to transport a two meter long antenna that weighed 200 pounds.....so we miniaturized the hardware while simultaneously expanding the antenna field cross section. We wanted to receive the entire ELF-VLF bands all at once, so we had to have an extremely broadband antenna....like four decades of bandwidth or more. You wouldn't believe the arguments I had with the reviewer at Physics Essays. He just couldn't believe that one could do what we did....and if it was indeed true, then why hadn't someone done it years ago?.., "and what makes you so smart", .so, of course, "this must be nonsense, etc....." Progress in physics is so bloody difficult because most physicists think that everything worthwhile has already been discovered....so they expect nothing new. This is negative feedback which, of course, makes the system stable, I suppose.

The one text book that includes diagrams of the antenna-external field interaction is listed as one of the references in the Physics Essays paper. Sorry, I can't remember the name of the author or the title.

John Sutton, Ph.D."

https://web.archive.org/web/20120722112702/http://www.unusua...

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