In recent years an increasing amount of oceanographic data has become available. This includes
observations as well as data from hydrodynamic ocean models. Validation is required for establishing the necessary
confidence in new sources of data. Generally ocean models and other data sources such as satellite imagery are validated
by comparing the output to conventional observations or the output of established ocean models.
Methods of comparison used in literature range from refined statistical methods to comparisons of snapshots. This work
collects descriptions of some of the most widely used comparison methods. The capabilities and limitations of each
method are demonstrated using examples from modelled and observed oceanographic data. The work has a particular
focus on how to determine discrepancies on vertical gradients in the oceanographic parameters since acoustic propagation
is sensitive to errors in the sound speed gradient.