Abstract: In recent decades, advanced navigation equipment such as radar, global navigation satellite systems, and electronic chart display and information systems have been widely used in ship navigation, significantly improving navigation safety. However, major accidents such as ship collisions, groundings, or strandings still occur frequently. Analysis indicate that some of these accidents are related to inadequate marine geographic information support for ship navigation. To address this problem, based on a brief analysis of the current status and existing problems of marine geographic information support for ship navigation, we first propose the concepts of base-state, new-state, and transient-state marine geographic information and their support products.Second, we analyze the characteristics of the three-state support products and their roles and functions in ship navigation support. Finally, with a focus on how to realize the three-state fusion support mode, an in-depth analysis is conducted from four aspects,including the fusion support scheme, process, effectiveness, and key issues to be resolved. The research findings can provide a referen‑ce for addressing the bottleneck of insufficient data currency in the existing marine geographic information support and further enhancing navigational safety.