We describe a molecular dynamics model for dissociable, polarizable water. The model, which describes both the static and dynamic properties of real water quite reasonably, contains the following features: Self-consistent local fields are calculated in an extension of an earlier algorithm in which the dipole moments of the water are treated as dynamical variables. An intramolecular three-body potential assures that the molecular properties of water are in agreement with experiment. Ewald methods are used to take account of monopole-dipole and dipole-dipole as well as monopole-monopole interactions. The model was optimized using a Monte Carlo procedure in the parameter space which is described.