Speed of sound calculation?

I've been looking at the raw speed of sound data from an AWAC deployment from 2004 and I came across the following discrepancy:

For a particular AWAC profile where the salinity was set by the user as 16 and the sound speed was Measured, the AWAC's calculated speed of sound was reported to be 1513.3 m/s for a transducer depth of 8.15 meters and a transcuder temperature of 25.715 degrees C.

I tried using the same salinity, temperature, and depth with the UNESCO (Chen Millero), DelGrosso, and Mackenzie formulae.  They calculate speed of sound respectively as:
1515.86
1515.702
1515.66

while a 2 m/s difference in speed of sound isn't likely to make a large difference, I would like to know what equation you are using for the speed of sound calculation.  Any insight would be helpful

We will look into this over the next few days and get back with an answer early next week.

Thank you for pointing out the problem.

Best regards,
Oistein Hurum

This has been confirmed to be an error in the software. We are using the UNESCO formulae but the error was not related to the implementation of the equation. The implications for the velocities could be an error of about 0.2%. The error will be fixed in the next software release.

Again, thank you for reporting the error.

Best regards,
Oistein Hurum