This chapter differs from the previous chapter by using sources in unbounded fluid as Green functions. Thus also the free surface (including ship waves) around the hull must be covered by source panels. The described method includes the interaction of oscillatory and stationary potentials; the latter is assumed stationary not in inertial, but in ship-fixed coordinates for higher accuracy. Also the method to satisfy the radiation conditions (no disturbance from outside, no wave reflections) is important for accuracy: for the stationary flow, a back shift of sources by one panel length is used, whereas for the oscillatory flow damping is applied everywhere on the free surface.