CRUCIAL aims at investigating the application of CryoSat-2 data over inland water with a forward-look component to the future Sentinel-3 mission. CryoSat-2's primary instrument is SIRAL (SAR Interferometric Radar Altimeter). SIRAL operates in one of three modes; Low Resolution Mode (LRM), Synthetic Aperture Radar(SAR) and Interferometric Synthetic Aperture Radar(SARIN). One year of Cryosat2 SAR L1B and LRM data have been processed over inland water targets. The waveform shapes have been analysed and behaviour with terrain and water distribution investigated. A new SAR retracker has been developed as well as hydrological modelling started for the Ganges-Brahamaputra and Mekong. Progress has been made in the processing of SAR FBR burst data to construct multi-looked waveforms at ground points spaced some 300 m along track. This processing utilizes FFT, stacking, range migration and combination of over 200 waveform looks at the ground target. The high along-track sampling of CryoSat-2 altimeter in SAR mode thus offers the opportunity to recover high frequency signals over certain regions of the Earth’s surface. Test results of 23 Aug 2013 with CryoSat-2 travelling S-N across a small tributary into Rio Tapajos, the broad Rio Tapajos, Rio Arapiuns, and then 4 braids of the flooded Amazon have yielded results of high consistency. The waveforms over water are identified by applying a detailed river mask to isolate the rivers from adjacent waters. The inland water waveforms are retracked to extract the height and converted to an orthometric height (relative to EGM08). Results show that the rms over broad rivers are at the few centimetre level. A hydrologic modelling approach is under development. Unlike previous ESA altimetric missions the modelling is based on a virtual station approach as the CryoSat-2 orbit is non-repeating. Studies over the Ganges-Brahmaputra use input meteorological data, the MIKE -11 hydrological model and the ensemble Kalman filter to estimate discharge. Other hydrological studies over the Mekong use CryoSat-2 for the virtual stage and Landsat river widths to infer discharge from statistically based formulae linking river height and stage to discharge.