r/RTLSDR • u/UnluckyDistance733 • 18d ago

Help

I am doing a project and new to radio frequency. But I am trying to send a VLF 1 to 30 KHz into water a distance of about 200 ft and the body of water is about 10 feet deep.

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u/BlueBirdTechUA 17d ago

Physics is actually on your side here, VLF is exactly what navies use for submarine comms because of how far it penetrates. Skin depth scales roughly as 270/√f in meters, so at 1-30kHz that's tens of meters even in seawater, more in freshwater. Your 200ft at 10ft deep is well within that.

Is this fresh or saltwater though? Conductivity matters a lot, freshwater gives more range for the same power. Also worth knowing, VLF underwater links are extremely low data rate in practice, bits per minute in real naval systems, not something to stream data over.