As assets are engaged to collect data and intelligence on the entities or parties of interest to a defense or security operation, much of the collected data are represented in electronic form and subsequently stored in an assortment of files or databases. It is also typical that these data or information need to be shared with others involved in the investigation, task group, coalition, or security force. The effectiveness of this sharing is ultimately judged by how well the receiving party understands the information it has received. In this paper we examine the commonality of concepts between information systems in the Canadian defense and security regime. Specifically, we consider components of the National Information Exchange Model (NIEM), the Canadian Naval Positioning Repository (NPR), a port clearance structure, and a messaging structure that evolved out of a Canadian defense research and development effort. We then investigate the performance of graph-based approaches for automatic schema matching over these schemas. The information structures, or schemas, are examined using the open-source software for combining match algorithms (COMA). Results of the investigation show how the diverse terminology in maritime defense and security introduces unnecessary differences in the vocabularies (e.g., using vessel, ship, or identity as the descriptor for an object). Results also show how discrepancies are introduced through data typing, the structure itself, and semantics. Overall, the investigation indicates that the graph-based methods do not appear to offer a way of automating structure matching while maintaining confidence in the output for schema used across the different systems underlying the Canadian MDA.