One of the main challenges of using marine controlled-source electromagnetic (CSEM) sounding for hydrocarbon detection has been a relatively low-resolution and restricted depth penetration. In addition, the use of CSEM in shallow waters has been perceived as particularly difficult. A new, robust method for enhancing marine CSEM subsurface response is particularly useful in shallow waters. The method is designed to reduce acquisition imprints and attenuate the dominant primary airwave contribution. Synthetic examples show that it is possible to detect thin, deeply buried 3D resistive bodies in a shallow-water environment with a complex resistivity structure. The results highlight the importance of a sufficient signal-to-noise ratio.