Methods and systems to assess in near real-time defects in seismic data resulting from noise and seismic data acquisition-system deviations during a marine survey are disclosed. Methods and systems apply forward modeling to a model of a subterranean formation to generate synthetic seismic data based on the noise and deviations in the seismic data acquisition system. The synthetic seismic data represents the seismic data that would be collected by a marine survey carried out on a subterranean formation with the same structure as the Earth model and includes defects that result from the noise and deviations in the seismic data acquisition system. Error estimation is applied to the synthetic seismic data in order to assess the defects at different stages of seismic data processing.