Performs systematic laboratory investigations on the influence of the spreading procedure on the surface viscosity, the surface potential and on the morphology. The latter aspect is being studied with the help of 'Brewster Angle Microscopy' (BAM), while the molecular structure of the system slick/adjacent water layer is being investigated by 'Infrared Reflection Absorption Spectroscopy'. Both methods allow in situ investigations of the monolayer at the air water interface without disturbing the structure and morphology of the film, though the authors confine themselves to BAM investigations. Comparison with scatterometer results obtained over biogenic and man-made sea slicks during the SIR C/X-SAR campaign illustrate the morphology aspects and their importance for the simulation of biogenic sea slicks.