Dynamic coupling between a steady state boundary layer flow over a fluid-saturated porous bed with the Darcy flow occurring in the bed is analyzed by employing an appropriate boundary condition to account for the tangential slip at the permeable interface separating the two flows. Numerical solutions of the resulting nonlinear boundary value problem, obtained by the shooting method, are presented for different values of the permeability parameter A" of the bed and the characteristic Reynolds number R of the potential flow impinging on the bed. It is shown that under experimental conditions for whichK2R<1, there exists a sublayer attached to the bed, in which the normal velocity of the fluid is directed upwards, that is, opposite to that of the potential flow.