Summary In deepwater environments where seismic recordings are made using ocean bottom sensors such as nodes (OBN) or cables (OBC) it is possible to produce two independent images of the subsurface using up-and down-going wave-fields. The 4Dsignals should be nearly identical on these wave fields but the 4D noise differs greatly. A weighted stack of the up-going and down-going 4D differences based on their similarity is shown to suppress the 4D noises while preserving the signal. Tests of this method on deepwater OBN data acquired in the Mars field shows good results. Weighted Stacking of the Up-and Down-going 4D difference Figure 1 illustrates ray-paths for up-and down-going waves for an ocean bottom sensor geometry.