good point. I like the idea of using sound waves to communicate with the submarine. I'd use a piezo buzzer because it would be louder. Yes/No? Then measure the sound waves in the pool and program submarine to change direction by hearing responses to sound waves frequencies. Communicate like a whale! 8)
IR gets absorbed by water very rapidly probably within 1,000 wavelengths or so so your comms range would be extremely limited.
encryptor:
I'd use a piezo buzzer because it would be louder. Yes/No? Then measure the sound waves in the pool and program submarine to change direction by hearing responses to sound waves frequencies. Communicate like a whale! 8)
That's not likely to work unless you use transducers designed for underwater use - see my reply #8.
4 -5 feet is not too deep, could you use plastic fiberoptic cable and a surface buoy? And a modulated 5mW laser may be better than the IR signal, especially range and power. Use a phototransistor for detecting the laser pulses... I've done similar around the lab for transmitting Morse Code between Arduinos and the phototransistor works even in ambient light - but you may wish to consider a optical bandpass filter anyway.
Just a thought... but it does make things more complex.
Ray