Post-adoption and continuance use of maritime digital platforms and inter-organizational information systems, such as Port Community Systems (PCS), is often overlooked in the literature. This study focuses on the benefits associated with using PCS to coordinate port calls, and the purpose is to identify and explain how different mechanisms influence the continuance use of PCS. A framework that combines Organizational Information Processing Theory, Technology Continuance Theory, and design science is applied to a longitudinal single case-study in Sweden. The data was collected using 21 interviews with port call actors, two observations and two archival documents. The findings revealed how organizational, regulatory, and labour-related mechanisms cause information quality deficiencies, undermining the satisfaction and continuance use of PCS. The study further proposes mechanisms to enhance the satisfaction and continuance use of PCS. These mechanisms are critical to achieve the economic and environmental benefits of PCS.