Data transmission in the open sea

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 :slight_smile:

Harry94:
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 :slight_smile:

More research is needed on your part. Even getting an antenna wet can change the impedance enough to stop most of the power at VHF, UHF and microwave frequencies.

Paul

Harry94:
I am currently doing my final project for my studies.

Could I use BLE or RF for example?

BLE (Bluetooth Low Energy) is an RF (Radio Frequency) technology.

Whilst you probably know the distance you want to cover, you have not revealed that information to the forum, so its going to be difficult for you to get realistic advice.