Identification of early warning criteria for rough sea ship navigation using high-resolution numerical wave simulation and shipboard measurements

Abstract. The analysis of ocean surface waves are essential to ensure a safe and economical navigation. Since 2010, different onboard observation data from a bulk carrier have been colledted for 6 years, including high-risk shipping regions in the Southern Hemisphere with strong ocean currents. For four rough sea cases, high-resolution numerical simulations of ocean waves, including the effect of wave-current interaction on ship navigation, have been performed using the WAVEWATCH III model. The simulations considered the ocean surface wind force from the widely used grid point value database NCEP-FNL and ERA-Interim. Aimed at providing practical suggestions for safe navigation by avoiding possible high-risk ocean regions as well as the construction of a more effective and efficient optimum ship routing system, the model results were validated based on onboard observations, followed by discussions on the responses of ship motion and navigation to wave states at different levels. Finally, identification of the early warning criteria, including various operational ocean parameters, is provided for ballast and loaded ships sailing in rough seas.