This standard describes the measurement systems, procedures, and methodologies used for the beam aspect measurement of underwater soundpressure levels from ships for a given operating condition. The resulting quantities are reported as nominal source level values in one-third octave bands. It does not require the use of a specific ocean location, but the requirements for an ocean test site are provided. The underwater soundpressure level measurements are performed in the far-field and then corrected to a reference distance of 1 m. This standard is applicable to any and all surface vessels either manned or unmanned. This standard is not applicable to submerged vessels or to aircraft.Measurement systems are described for measurement of underwater soundpressure levels and also the distance or range between the underwater transducers and the subject vessel. Processing and reporting of the data are described, and informational guidance is provided. This standard does not specify or provide guidance on underwater noise criteria.