Maki, AtsuoAtsuoMakiMaruyama, YuukiYuukiMaruyamaKatsumura, KeijiKeijiKatsumuraDostal, LeoLeoDostal2024-10-242024-10-242024-10-01Journal of Marine Science and Technology 29 (4): 910-919 (2024)https://hdl.handle.net/11420/49869The broaching that follows the surf-riding is a dangerous phenomenon that can lead to the capsizing of a vessel due to its violent yaw motion. Most of the previous studies on surf-riding phenomena in irregular waves have been conducted by replacing irregular waves with regular waves. In contrast, this study provides suggestions on how to directly calculate nonlinear surge motion in irregular seas. In this study, the statistical aspects of the surf-riding phenomenon are first presented. Then, under several approximations, we show how to calculate the probability density function theoretically. Although the results obtained are based on strong approximations, it is found that the nonlinear surge oscillations in irregular following seas can be explained from a qualitative point of view.en0948-428020244910919SpringerBifurcationBroaching-toIrregular seasStochastic differential equationTechnology::623: Military Engineering and Marine EngineeringNatural Sciences and Mathematics::510: MathematicsJournal Article10.1007/s00773-024-01027-xJournal Article