How to transmit data underwater?

At the moment i have shifted my focus to building a CNC machine. I Figured it would be very helpful in all aspects of my project, for one circuit board "etching". I plan to sometime in the near future build the schematics that we have put together. Do you think this would be a good idea or should i iron out any other details other then the last corrections to the schematics.

As a summary i will be broadcasting at 200 baud with a center frequency of 200 kHz which has been set the various Caps and resistors. I plan to start by using a FKS method of turning one frequency on and off. The Receiver will attach to my computer via USB. The transmitter will attach to a 12 VDC car battery and to the arduino.

Question: Do you know of any free software like visual studious which i could use to display the data being received?