The standard specifies the required precision for:
is an international standard approved by the International Organization for Standardization (ISO). Despite its age (1979), it remains the definitive technical reference for measuring the speed of sound in water specifically for the calibration of echo sounders and sonar systems used in shipbuilding and hydrographic survey. iso 5488 pdf
Here is the most critical warning regarding your search for "ISO 5488 PDF." You cannot legally download a free, unwatermarked PDF of ISO 5488 from file-sharing sites (such as Scribd, PDF Drive, or random engineering forums). The standard specifies the required precision for: is