The regulation of antifouling paints in the European Union falls under the Biocide Products regulation (BPR, Regulation (EU) 528/2012) and consists of two assessments: an environmental risk assessment (ERA) and an efficacy assessment. The efficacy assessment is key for the placement of an antifouling paint on the market as a biocidal product must be shown to be effective to gain approval. At the same time, the BPR states clearly that biocidal products should not be excessively toxic, i.e. release active substances to the environment in excess of the minimum necessary to achieve the desired effect. This report provides a summary of current knowledge, based on several years of research, about efficaciy and excess toxicity of antifouling paints intended for use on leisure boats in the Baltic Sea region.