A hydrophone calibration system is a very important tool which is used to achieve precision and certainty of measurements in underwater acoustics. Hydrophones are referred to as sensors that are responsible for the detection and recording of underwater sound waves, and accordingly the method is applied in many fields including, but not limited to, oceanography, marine biology, environmental monitoring, and defense applications. In order to realize the exactness of their devises by a good calibration system it's just a must.