A C-grid
is a composite grid whereby three variables are solved for. It is
composed of three subgrids. The first subgrid shows a mesh for the
variable 
(free surface height), the second shows a mesh for the
variable U (West--East transport), and the third shows a mesh for the
variable V (North--South transport). The overlay with the respective
shifts (see Figure 16, Figure 17 and
Figure 18) comprises the
composite grid.
