Seismic data with different resolution are normally acquired in separate surveys. In the present survey both conventional reflection seismic data with airgun source and high resolution sparker data have been acquired in the Kattegat, - the costal waters of Denmark. The data are recorded with a small time delay between activating the sparker and the airgun. Data have been submitted to a conventional seismic processing. Since the two datasets are acquired almost exactly at the same positions it facilitates a combination of the two seismic sections. Wavelet conversions have been made and a weighted combined stack of the two datasets has been established. This has produced a stack with all essential information, with a wide spectral content for the near surface intervals and a low frequent content for the deeper parts, where otherwise the sparker data shows no significant energy.