Mathematical modeling has been used to characterize and validate the working mechanisms of tin-free, chemically-active antifouling (AF) paints. The model-based analysis of performance data from lab-scale rotary experiments has shown significant differences between antifouling technologies as regards the biocide leaching and the surface polishing processes. Hence, the modeling framework developed in this work is built so as to describe any generic, chemically-active AF paint through model parameters, the values of which can be obtained or adjusted from relatively fast measurements. The detailed quantitative information on reacting A F paint systems obtained can be used for accelerated product optimization purposes, thus facilitating the transition to cleaner antifouling technologies using, for example, fast-degrading natural or synthetic bioactive components. (c) 2006 American Institute of Chemical Engineers.