“…We mention that the f-plane approximation for the deepwater wave problem possesses an explicit solution: Gerstner's solution to the deep water wave problem [7,8] can be generalized, cf [25], to describe deep water waves in the geophysical context. We emphasize that any solution of the f-plane approximation which has the property that the pressure is constant along the streamlines has to be a vertical translation of the solution described in [25], cf [26]. Moreover, the solution found in [25] may be adapted to describe geophysical waves travelling over uniform currents, cf [27], where the motion of the fluid particles in dependence of the current's strength and the direction of propagation of the wave is also analysed.…”