Acoustic multibeam measurements and satellite predictions are often considered to be competing methods to detect seafloor topography. In opposition to that the supplementing aspects will be pointed out to aim at geophysical interpretations. Advantages and limits of the indirect method will be briefly explained starting with the correlation of sea surface heights and sea floor topography to derive gravity anomalies. In the next step the method of forward modelling will be explained. Finally, differences are shown comparing predicted and measured bathymetry of the Eltanin Impact Area, South Pacific, as well as predicted gravity and measured bathymetry of the Weddell Sea.