On the basis of an understanding of the ocean current produced under the combined forces of wind stress over the sea surface and horizontal pressure gradient force caused by the uneven distribution of seawater density and the elevation of sea surface

we obtained the unsteady analytic solution of the variation with time of ocean surface current velocity corresponding to the time variation of the above two forces

and the unsteady analytic solution for variation of seawater density with time by considering only the vertical turbulence. To meet different needs

the above solutions may be written in two forms for short and long time predictions. After some simplification the analytic solution was used to predict surface ocean current velocity for meteorological navigation in the North Pacific. The monthly average current field was first obtained to get the necessary parameters for selecting the initial shipping route in the North Pacific and Bohai and Yellow Seas. The wind current field was then calculated by means of the simplified analytic solution to provide realistic bases for prediction of the ocean surface current field so that the optimum navigational route can be known several days in advance.