Speed of Sound in Water

The sound speed can be measured by mounting a small acoustic transducer and reflecting surface at a known distance from the acoustic center of the transducer. Then since the distance from the transducer to the reflector is known, the time it takes for the pulse to go out and get reflected can be used to calculate the speed of sound in the water.

A second method is to use a piece of equipment call a sound velocity probe. A sound velocity probe is dropped into the water and lowered to the seafloor and then raised back up to take two casts of data: a downcast and an upcast. The probe takes temperature readings, salinity readings and pressure readings per time. This data is then processed in order to give the sound velocity versus water depth.