This guide provides current information and equations for calculating the speed of sound in sea-water as a function of temperature, salinity and pressure (or depth).

Contents

• Two simplified equations are those derived by Mackenzie and Coppens
  
  
• UNESCO equation: Chen and Millero: The international standard algorithm, recalculated following the adoption of the International Temperature scale of 1990.
  
  
• Del Grosso's equation: Preferred to the UNESCO equation by some researchers, also recalculated following the adoption of the International Temperature scale of 1990.

Also available:

• Pressure or Depth: Converting from pressure to depth or from depth to pressure.
  
  
• Uncertainties: Advice on the accuracy and precision of the various equations.
  
  
• References: Up-to-date list of references on sound speed in sea-water.
  
  

For further information, contact Justin Ablitt