I am looking into constructing a small submarine with a Raspberry Pi. This is just for a hobby project but my idea is to have it communicate with the surface wirelessly. I know that normal radio waves will not work very well so I was thinking of using some type of Ultrasound device where a transmitter/tone generator is placed in the water and the submarine has a receiver/microphone that can pick up the sound waves transmitted.
I have read that sound waves are easily transmitted underwater so this is where I came up with this idea. I am wondering if anyone has already done a project like this in the past or knows where I can find more information on it? I have never really worked with sound/wireless transmission so its all very new to me. Any help is greatly appreciated!