The invention relates to a cargo transfer system (200) that provides improved safety for users. When a cargo item (304) is being transferred from a transport vessel (300) to loading area (306), the system (200) provides a warning of the impeding delivery of the cargo item (304) to persons in the loading area (306). Similarly, when cargo item (304) is being transferred onto vessel (300), a warning is provided to persons in the relevant area (306) of the vessel (300). The system uses sensors (226, 228, /10, 12, 40) provided adjacent to the side of a ship (300) to indicate the presence of the cargo item (304) to a programmable logic controller (PLC) which activates a strobe (53) and siren (57) to provide a warning to people in the hold or on shore (306). The system also makes provision for the position of the boom (206) of a crane (200) that loads or unloads cargo items (304) to be monitored by the PLC to provide an indication of cargo item (304) approaching the hold of the ship (300) or approaching the shore (306).