A method for retrieval of the spatial variations of the sea surface mean square slope (MSS) in sunglint imagery is applied for analysis of surface signatures of the internal waves. It is shown that internal waves are well visible via modulations of the sea surface MSS, enhancement/suppression of the MSS takes place in the zones of IW-induced surface current convergence/divergence. The results clearly demonstrate a highly feasible approach for investigation of the Ocean internal waves surface signatures.