Abstract
Measurements of hydro-acoustic noise emitted from vessels are a.o. a subject of the tests carried out in the control measurement ranges of the Navy. The measurements are performed both on anchored and floating vessels. Acoustic field of vessels is changing along with their speed changing and is associated with acoustic activity of wave sources installed in vessel's hull (main engines, electric generating sets, reduction gears, pumps, shaft-lines, piping, ventilating ducts etc) as well as hydro-dynamic sources such as screw propellers and water flow around the hull [5, 7]. Vibration energy generated by the onboard devices is transferred through ship structural elements to water where it propagates in the form of hydro-acoustic waves of a wide frequency band.