Note particularly the VM scaling! It should be between 0.9 and 1.1; normally be close to 1.0. Be sure to save this calibration result with your configuration files (.svm). The resulting calibration parameters will then be used automatically for all subsequent data collection surveys.
If you record data, keep track of the calibration parameters you use because the parameters are not stored with the data files. The best way to do this is to record new configuration files every time you change configuration or recalibrate, and to use the same name for both data and configuration files.
Particular care should be taken to ensure the erroneous readings are not included in the calibration data set. If the calibration is performed in shallow water, select a corresponding depth range in the Configuration... dialog. The user can also choose which cells to use in the calibration such that any shears can be removed. If the VM scaling is outside of 2%, ie 0.98 or 1.02, reducing the number of cells can often give a better result. In general the best result is the correct one.