Marine biofouling compromises function and reliability of marine equipment, causing considerable economic and environmental damage. Biocides for fouling prevention are increasingly avoided for environmental reasons, and the development of effective nontoxic antifouling coatings requires better understanding of the interactions between fouling organisms and surfaces. We try to understand how surface properties affect the behaviour and attachment of marine organisms, and which strategies and chemical ¿glues¿ they use for attachment. An essential part of this research is development of antifouling polymeric materials. In certain polymer coatings we observe a clear thickness dependence on the antifouling efficacy, suggesting that polymer structure and swelling vary with thickness. We ask for beamtime to clarify the structure of such a polymer to better understand its antifouling properties.