Analytical criteria for risk assessment of ships in random seas are important for the development of new intact stability criteria and also for the first design stage, where many ship designs have to be compared. The analysis is performed by Stochastic Averaging. The results are compared to those obtained by Monte Carlo simulations. We use extended wave modeling by means of two independent stochastic processes realizing a traveling wave with random phase and amplitude corresponding to a prescribed sea spectral density. The righting lever curve in waves is approximated by a polynomial, while quasistatic equilibrium of the analyzed ship in waves is assumed. (© 2010 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)