Sonar systems are an integral part of the submarine’s design. To complete many of the objectives in the competitions, the submarine must be able to locate pingers, or underwater speakers, emitting sound at fixed frequencies. The solve this problem, our submarine has an array of four hydrophones (underwater microphones). These hydrophones are all separated by a fixed/known distance. By analyzing the phase difference of the incoming waves to the array of hydrophones, we can triangulate the location of the pinger. To accomplish this, the hydrophone boards process and convert the incoming data.The hydrophone boards consist of two sub-boards: the microcontroller board and the pre-amplification board. The pre-amplification board is placed at the same location as the hydrophones, in a small housing at the bottom of the submarine. The board amplifies all incoming signals from the hydrophones, and transmits them off to the main housing. In the main housing, the microcontroller board converts the analog signals to digital, and sends the digital data to the main computer.