Development of a numerical marine weather routing system for coastal and marginal seas using regional oceanic and atmospheric simulations

The primary objective of this study is to develop a new weather routing system for vessel navigation in coastal and marginal seas based on the A-star algorithm. The cost function inherent in the original A-star algorithm is modified to account for oceanic and atmospheric conditions around the vessel of interest. Three options are introduced to search for optimal paths with the shortest travel distance, shortest travel time, and minimal fuel consumption. An avoidance algorithm for unsafe conditions is further incorporated to exempt any arbitrary area from the navigation solution. Furthermore, a compact ocean circulation model based on the Regional Ocean Modeling System executable on typical laptop PCs is configured for a vessel-borne weather routing system; the system is successfully applied to evaluate the optimal vessel paths in the Seto Inland Sea, where high-frequency tidal currents modified by complex topography make it essential to alter the vessel's speed. •A new weather routing system based on the A-star algorithm is developed.•The cost function is modified to account for oceanic and atmospheric conditions.•Three options are introduced to search for optimal paths by the developed system.•An avoidance algorithm for unsafe conditions is incorporated.•An ocean model executable on laptop PCs is configured for a weather routing system.