The Mitsubishi Heavy Industries Group has built many state of the art special purpose ships for many years. To fully demonstrate the performance of underwater investigation systems and to localize the escape behavior of marine life, it is important for these special purpose ships to reduce the underwater radiation noise from the ship itself. Our group developed a method for predicting underwater radiation noise in a wide frequency range using experimental data and large-scale analysis technology, and enabled a more silent design corresponding to the cruising speed of the special purpose ship. In the underwater noise measurement after ship construction, it was confirmed that the prediction method has good accuracy and the special purpose ship has an excellent quietness with low underwater radiation noise.