Knowledge about the characteristics of fluid mud in ports and waterways would allow safer navigating through fluid mud. The properties of the fluid mud determine the feasibility of navigating vessels through the fluid mud. Seismic waves have the potential to help characterize the fluid-mud layers, especially when both P- and S-waves are used. To investigate the possibility of using reflections measurements for more accurate fluid-mud characterization, we perform ultrasonic reflection experiment on fluid mud from Port of Rotterdam. We apply seismic interferometry to the measurements to retrieve non-physical (ghost) arrivals from inside the fluid mud layer and to eliminate the kinematic influence of the water layer above it. We show how we retrieve P-wave ghost reflections and analogously how we can retrieve S-wave and P-to-S-converted ghost reflections.