The application of intact stability Weather Criterion to the new large passenger ships leads to more stringent requirements than the application of current subdivision and stability rules for damage ships. A critical analysis of Weather Criterion in its hystorical development and in the present version has thus been conducted. In this paper, the calculation method of the rolling amplitude is examined with the aim of identifying weak points needing further studies and to propose some interim modification of existing procedure. It appears that the formulas or graphs used to compute the relevant quantities for the evaluation of ship safety on the base of Weather Criterion appear to overestimate roughly the environmental action. A proposal to correct the evaluation formula for the factor "r" is provided.
