The objective of this paper is to analyze the effect of the pollutant such as petrol-emulsion on the electromagnetic scattered filed by a maritime surface. Firstly, we investigate the pollutant influence on the maritime surface and physical properties of seawater. Then, we simulate the variation of electromagnetic scattering of the clean maritime surface and also the polluted surface. In this study, the clean and polluted seas are modeled using a semi-empirical spectrum. The simulations of scattering coefficients are realized by using the Forward-Backward Method (FBM), the Composite Two Scale-Model (CTSM) and the Small Slope Approximation (SSA) in monostatic and bistatic configurations. The effect of the pollutant on the electromagnetic scattering of a maritime surface has been studied as function of oil percentage, angles, frequency values and polarization state.