Short range under-freshwater RF data communications

Thread Starter

WaterRunner

Joined Apr 11, 2016
5
Hi, Looking for suggestions on low power, underwater data communications in fresh water. Range can be as low as 14 meters. I understand that most underwater communications use ultrasound, but one reason is slat water conductivity. Maximum amount of data is approximately 20 bytes at a time.
Thank you.
 

Papabravo

Joined Feb 24, 2006
14,701
VLF is the only way to go through water. Unfortunately that is not conducive to data transfer at any reasonable speed. The required antenna size will knock your socks off.
 

Thread Starter

WaterRunner

Joined Apr 11, 2016
5
VLF is the only way to go through water. Unfortunately that is not conducive to data transfer at any reasonable speed. The required antenna size will knock your socks off.
I don't think so. Radio does work in fresh water, and coiled antennas can be used. Interested to see if anyone has direct experience with this.
 

Sitara

Joined May 2, 2014
57
Hi WaterRunner,

This is a known and (to an extent) solved problem. The people who did so are the Radio Controlled Submarine enthusiasts. In a nutshell, provided the vhf dipole antenna is COMPLETELY sealed against water ingress, you can get a range of around 50 metres tops, in fresh water.
These links should help you out:
https://en.wikipedia.org/wiki/Radio-controlled_submarine (look at the reference links at the end of this article, which includes the pdf link which Bertus provided in post #6)

http://www.rc-submarines.net/radios.html



 
Last edited:

Thread Starter

WaterRunner

Joined Apr 11, 2016
5
Hi WaterRunner,

This is a known and (to an extent) solved problem. The people who did so are the Radio Controlled Submarine enthusiasts. In a nutshell, provided the vhf dipole antenna is COMPLETELY sealed against water ingress, you can get a range of around 50 metres tops, in fresh water.
These links should help you out:
https://en.wikipedia.org/wiki/Radio-controlled_submarine (look at the reference links at the end of this article, which includes the pdf link which Bertus provided in post #6)


Thanks Sitara, this is highly relevant.
 
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