The world crucially needs to reduce the level of emissions being released in the environment in order to combat climate change. With the global population increasing and economies continuing to grow, the circular economy has been heralded by many as the potential solution to economic prosperity whilst also reducing primary resource use and emissions. However, the existence of environmental rebound effect has the potential to severely limit the emission reductions of the circular economy by increasing consumption elsewhere. This paper focuses on the definition of economic rebound effect and on its impact on a peer-to-peer boat sharing platform in Finland. A survey completed by users of the platform allowed for the quantitative analysis of environmental rebound effect experienced by the users and also provide insight into the consumption behaviour that created the most negative consequences. Rebound was experienced by almost all users with almost a third of users experiencing a backfire in which their overall emissions increased as a result of consumption made possible by the economic benefits of shared access. Primary production and the substitution of air travel for the leasing of a boat created large reductions in emissions, however, this was counteracted by increases in personal use and increased air travel by others. This real-life study of environmental rebound effect shows both its existence and impact on the peer-to-peer sharing of boats in Finland.