The study presented in this work examines the use of Synthetic Aperture Radar (SAR) on-board the first European Remote Sensing Satellite (ERS-1) for the measurement of wind waves and discusses its applications such as wave data assimilation and inverse modelling. Over four years of directional measurements acquired by a heave-pitch-roll buoy moored in tropical deep waters around 150 km offshore are employed to investigate the mechanisms of SAR wave imaging and the retrievals of wave spectra from SAR images. For the first time the most widely implemented Max-Planck Institut (MPI) SAR...