A model is presented for studying ocean circulation problems taking into account the complicated outline and bottom topography of the World Ocean, To obtain an efficient scheme for the study of low-frequency, large-scale current systems, surface gravity-inertial waves are filtered out by the ''rigid-lid'' approximation. To resolve special features of the ocean circulation, such as the Equatorial Undercurrent, the numerical model allows for a variable spacing in either the zonal or meridional direction, The model is designed to be as consistent as possible with the continuous equations with respect to energy. It is demonstrated that no fictitious energy generation or decay is associated with the nonlinear terms in the finite difference form of the momentum equations. The energy generation by buoyancy forces for the numerical model is also designed in such a way that no energy ''leak'' occurs in the transformation from potential to kinetic energy. (C) 1969 Academic Press.