I am currently doing my final project for my studies. I am trying to send the heartbeat rate of a swimmer to a buoy in the open sea.
I was trying to do that underwater, but salinated water seems to be restricting for communication. Would it be possible to do that through the air, for example by placing the transmitter on the wrist (wristband) or the head (googles) of the swimmer. I know this means that the transmission will not be always possible as these parts can go underwater while swimming.
Is there a way to achieve that communication? Could I use BLE or RF for example?
Thanks in advance