This hands-on scenario was developed to introduce students to the concept of cumulative effects, why cumulative effects are a linchpin to managing for coastal impacts, and the challenges associated with managing for cumulative effects when faced with limited time and resources. By engaging in decisions while confronted by these cumulative effects challenges, students learn to apply the scientific and policy principles necessary to make their own management decisions. Coastal ecosystem management involves consideration of some of the most biologically diverse marine habitats, including kelp forests, seagrasses, and coral reefs. These ecosystems also represent a major interface of human activities and marine ecosystems, and are subject to impacts from both land and sea activities. Addressing cumulative effects in coastal ecosystems remain a challenge to both scientists and resource managers. Understanding why the challenge exists is an important first step in moving forward towards better integration of cumulative effects in future planning.