Cluster thinking has become increasingly important to maritime policy. In a European context a focus upon maritime clusters is seen as important for the understanding and promotion of competitiveness, innovation and economic growth in the maritime industry. However, a focus on clusters is not entirely without its problems. A cluster is an important but also intricate concept. This article addresses some main problems with the so-called cluster-based approach and sketches some new directions for work on maritime clusters. The article was written as part of a larger research project carried out at Copenhagen Business School, where the author has recently started the research network “Blue Denmark.dk — Research on Maritime Industries”.