This is the README that came with the CTD vertical profile during I5S 2009. The resolution is every 2db:
CLIVAR I5 2.0db downcast pressure series CTD Data
The file format is:
Pressure (db)
Temperature (ITS-90 degC)
Salinity (PSUs)
Dissolved Oxygen (uM/kg)
Transmissometer (0-5VDC)
Fluorometer (0-5VDC)
Potential Temperature (ITS-90 degC)
Sigma Theta (kg/m**3)
Dynamic Height (Dynamic meters)
Elapsed Time (seconds)