The numerical basis of FINEL 3D is the finite element method and uses the same grid as the 2-dimensional shallow water flow model FINEL 2D, which is extended in vertical direction with an arbitrary number of vertical gridpoints. This procedure makes the schematisation process quick and efficient as special features of the area of interest can be easily incorporated in the model.

FINEL 3D is also able to compute density currents resulting from cold-warm and salt-fresh interactions, and the combination of both.