This transaction set communicates the scheduled voyage details and port itinerary for ocean-going vessels. It is typically sent by ocean carriers or vessel operators to freight forwarders, shippers, port authorities, and other logistics partners who need to coordinate cargo movements. The transmission provides a complete overview of a vessel’s planned route and timing. The V1 segment identifies the specific vessel involved, the R4 segment specifies each port or terminal on the itinerary, and the V9 segment provides detailed event information—such as estimated arrival, departure, or cargo handling activities—at each location. The DTM segment carries the precise date and time references for these events.

For example, Maersk Line might transmit a 323 transaction set to DHL Supply Chain detailing the scheduled voyage of the container ship MSC Gulsun. The message would include the vessel’s registration in the V1 segment, followed by multiple R4 loops, each representing a port call: Port Said, Singapore, Shanghai, and Los Angeles. Within each loop, corresponding DTM entries would specify the vessel’s estimated time of arrival and departure, while V9 segments would indicate whether the event involves container loading, unloading, or transshipment. This allows DHL to track the vessel’s progress and coordinate their customers’ shipments accordingly across the entire trade route.