A linearized formulation for the unsteady forces experienced by supercavitating bodies is developed in terms of their added mass and damping coefficients. The formulation is general, but is applied here using an axisymmetric base flow. Expressions for the added mass, damping and restoring tensors are derived in a form suitable for incorporation in a numerical "flight" simulation tool for supercavitating vehicles. Disk and conical cavitating bodies are investigated. It is found that the added mass in surge can actually be negative for small values of the reduced frequency. The physical interpretation of this phenomenon is provided
