In containerised supply chains the market power has shifted from shippers being responsible for port choice to liner carriers and freight forwarders. If organised as merchant haulage on behalf of the shipper or consignee, the global sea freight forwarder exerts the biggest influence. But next to choosing an exporting and/or importing port, other maritime supply chain choices are of importance and incorporate a variety of carrier and mode selection decisions. The main purpose of this paper is to derive from case study results a new process-based approach to maritime supply chain choice modelling. The contribution refrains from empirically collecting port, liner carrier and mode choice criteria and their weightings from a freight forwarder's perspective. Instead, previous research findings are summarized and attention is drawn to insights into choice dependencies and potential coordination problems. Prior, modelled business processes serve as a basis for discussion with practitioners and are part of a linear but iterative case study research. Four global sea freight forwarders agreed to participate in the study. As a result, practical insights lead to the introduction of the new process-based approach to maritime supply chain choice modelling which stimulates further research.