“…The main sources of ship radiated sound are: (1) machinery noise generated by propulsion and auxiliary machinery such as engines, main motors and gears; (2) propeller noise generated by cavitation at or near the propeller and propeller-induced resonant hull excitation; (3) hydrodynamic noise from radiated flow noise, resonant excitation of cavities, plates, and appendages; and (4) cavitation at struts and appendages. The passive acoustic spectra of ship-radiated sound is extremely dynamic, containing both broadband signals and narrowband tonals at discrete frequencies [23,41] with source levels that can vary depending on ship conditions [42,47] such as ship speed [48][49][50], orientation [39] and maneuvers [51]. Ship noise has been previously found to be dominated by propeller cavitation, propeller singing due to physical excitation at the trailing edges of the blades, and propulsion or other reciprocating machinery [2,8,18,28,45,46].…”