Paper describes a method for prediction of extreme ship roll angles occurring during sailing in harsh weather. Rolling is coupled with other ship motions and exhibits highly nonlinear behavior. Ship capsizing probability is an extremely important issue in the ship design. Due to nonstationarity and complicated nonlinearities of both waves and ship motions, it is a considerable challenge to model such a phenomenon. In case of extreme motions role of nonlinearities dramatically increases, activating effects second and higher order. Moreover lab tests may also be questioned because of the scaling and the choice of sea state. Therefore data measured on the actual ships during their voyages in harsh weather provides a unique insight into statistics of ship motions. The aim of the work is to develop specific methods which make possible to extract the necessary information about the extreme response from relatively short time history. The method proposed in this paper opens up the possibility to predict simply and efficiently both short-term and long-term extreme response statistics.
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