Abstract: Theoretical modeling on the water blast response of the one-dimension naval structure coated with elastic foam is carried out. The concentrated mass-spring model was applied to describe the nonlinear behavior of the foam. An analytic model for the wet face response, inclusive of fluid/structure interaction is developed. The model addresses cavitation and incorporates the momentum of reconstituted water attached to the wet face. The first order DAA method is used to solve pressure in the spring-back and the succeeding phase. The fidelity of the analytic model has been assessed using FE simulations.