A method for calculating partially cavitating flows is presented. This method respects the impermeability condition on the profile in the vicinity of the cavity. The difficulties inherent in a scheme which gives a solution depending on the internal field organization, when the cavity is open, are analyzed. Several closure models are compared with the experimental results. This comparison shows the great variety of models that would have to be considered in order to give a proper account of the t(ac) law for three types of geometry. The pressure recovery study for one of the three geometries shows that pressure recovery can be simulated by a distribution of sinks distributed immediately downstream of the cavity, followed by a positive flux zone farther downstream. Validated by means of a finite-element calculation, the method proves its capability to take into account the effect of nonparallel confining walls placed very close around a foil of very small relative thickness.