Wetland Interferometric Synthetic Aperture Radar (InSAR) is a relatively new application of the InSAR technique, which detects water level changes in aquatic environments with emergent vegetation. It provides high spatial resolution hydrological observations of wetland and floodplains that cannot be obtained by any terrestrial-based method. However, InSAR observations are relative both in space and time and, hence, depend on terrestrial (stage) observations for calibration and validation. In this study we explore which SAR data type is most suitable for the wetland application, as well as explore the usage of InSAR for detecting water level changes in various wetland environments around the world. Our analyses indicate that longer wavelength SAR systems (L-band), horizontal (HH) polarization of the radar pulse, and short repeat orbits provide best results. Wetland InSAR applications include high spatial resolution water level monitoring, detection of flow patterns and flow discontinuities, and constraining high resolution flow models.