In the context of increased scale of carriers and vessel sizes, stakeholder opposition to port expansion and heavy regulation, ports prepare their strategic response. A port’s competitive strength strongly depends on its capability of developing or retaining competitive advantages. Ports consider options such as strategic partnerships, or any form of collaboration, which could help them to create more or alternative combinations of unique resources as sources of competitive advantage. Taking an extended resource base perspective, the competitive advantages of the Antwerp port cluster are analyzed, using both linear regression and factor analysis, for its integrated hinterland network area, on data of 59 port experts. The results of our analysis show that the port’s hinterland extension did not (yet) result in new sources of competitive advantages. This leads us to the reflection that we cannot assume integrated port clusters always lead to projected positive strategic outcomes.