Using nRF52840 to send data over open sea surface

[Harry94]

I am currently working on a project where I try to send data from a swimmer in the open sea to a point on the land (beach). I know that Bluetooth communications are blocked by the water, but would it be possible to achieve this communication whenever the wrist of the swimmer (wearable) is out of the sea? Will the sea environment allow this communication?

[Harry94]

Edvin

Well, there are two scenarios based on the range. If the the range can reach the shore then yes, it would be a phone. Otherwise, I could connect to an Arduino enclosed in a buoy in the open sea, and then with an antenna communicate with the phone on the shore.

awneil

How could I detect it then? Do you have something more efficient and long range in your mind?

Thank you both for the replies.

-Harry

[awneil]

Perhaps you need to define what, exactly, you mean by "detect" ?

Remember that we know nothing about what you're trying to achieve here!

http://www.catb.org/esr/faqs/smart-questions.html#goal

If the device is simply broadcasting a "beacon", then you can detect whether that is present or not without having to establish a connection.

Edvin said:

This doesn't sound like a case where BLE would be very suitable

So why, specifically have you chosen BLE?

Have you considered alternatives?

[Harry94]

I selected it because I am familiar with it and because of its range. I have considered more alternatives, but I am doing a research of what is possible. Any directives are welcome.

-Harry

[awneil]

Harry94 said:

Any directives are welcome

Still unclear what your goal is - what you're actually trying to achieve - so impossible to give much direction.

But I think the main directive is that BLE is not at all well-suited to this.

Note that the nRF devices can also do other protocols but, because of the water... submersion, anything 2.4GHz is probably not going to be great.