Dynamic buckling response of tubes immersed in water and subjected to an axisymmetric external throughwater pressure pulse is investigated using the finite element method. A loading routine describing the hydrodynamic net pressure, incorporating incident and reflected pressure pulses on the structure was developed. This is interfaced with the general-purpose finite element code ABAQUS to solve for the structural response which has non-linearity in both material properties and displacements. Idealized geometric imperfections in the radius are used in the finite element model to trigger the radial buckling mode. The same numerical procedure was employed to predict the dynamic buckling response of tubes subjected to impulsive loading in air. Comparisons are made with plastic flow buckling theory and experiments reported in literature.