This paper present a numerical simulation of electromagnetic (EM) signature of a sea surface in presence of pollutants (emulsion and layer). We have applied the rigorous Forward-Backward Method (FBM) and compared the results obtained with those given by the asymptotic models, the two-scale model (TSM) and small-slope approximation (SSA), in several configurations and for different acquisition parameters such as (wind speed, pollutant type, incidence angle, scattering angle, frequency band and polarizations state).