New equation for the speed of sound in natural waters (with comparisons to other equations)

A new equation for the speed of sound in sea water has been developed with validity not only for realistic combinations of the parameters salinity, temperature, and pressure, but with extension to pure water as well. This new equation, referred to as NRL II, has a standard deviation of 0.05 m/sec. Tables are presented comparing calculations using this new model to each of eight earlier equations. Graphs are also included indicating approximate corrections that could be applied to existing sound speed profiles, but it is recommended that such profiles be recalculated and new ones obtained according to NRL II.