BLE signal for underwater application?

[vishal]

Hello,

We have developed our application which included sensor and receiver using nRF52840 with SDK15.0. Sensor will goes underwater up-to 100meter depth level and transmitting data to receiver which have above of water.

But we observed when we put device into water then within few feets the BLE signal not getting. 

Actually I have read this click here they said underwater 63% signal losses, So nRF52840 long range mode upto 400-600meter. If 63% of 400m = 148meter range will get underwater but not getting.

Can anyone please provide How we communicate with wireless underwater upto 100meter atleast? 

If we used Zigbee protocol to communicate with both Is it possible to achieve 100m range underwater?

Thanks....

[Arne]

Hi Vishal, sorry I have to pour water into your wine. Simply forget to be able to transmit information over a distance of several meters not talking about 100m in water. The technological problems you will face for such a task are much much harder than what you faced developing bluetooth apps. Water is a conductor and thus electromagnetic waves have problems to travel larger distances. A big problem for submarines. There is I think something they call a channel at very very low frequencies, thats what submarine use. However, the military opponents can pick up this signal as well. I presume thats why nature has equipped animals like wals with the ability to produce ultra sound as well as low frequency sound pulses that are able to travel longer distances. But these hydrophone transducers are quite tricky on there own. If you dive into this matter you´ll soon find out. My recommendation: Get expert advice and if you have money just buy what you need. The quickes and maybe cheapest solution is a wire between your devices, if feasible in your application. Regards and Good Luck Arne Lorenzen

[vishal]

Thanks for your suggestion.

[awneil]

(reply to off-topic comment deleted)