A theoretical hydroelastic analysis of an axially loaded uniform Timoshenko beam, with intermediate end fixities, undergoing hydrodynamic impact-induced bottom slamming, is presented. The underwater part of a marine craft is modeled as a lightly damped flexible beam, which rises out of the water in rough seas, and slams against it at a very large vertical velocity. This causes highly intense, localized hydrodynamic impact pressure sweeping across the beam at high velocities, setting it into high-frequency vibrations, predisposing it to plastic deformation and/or fatigue failure. The natural frequencies of the structure depend on the slenderness ratio, axial load, and end fixities. The natural frequencies and modeshapes are generated through the Eigen analysis. The changing wetted surface is the prime complexity of the problem. The relative velocity between fluid and structure is considered to establish the hydrodynamic pressure (radiation and impact). Normal mode summation method is used to analyze the transient structural vibration, for various impact speeds, deadrise angles, end fixities, and axial loads on the beam. The primary aim is to establish the zone of prominence of hydroelasticity, study the maximum dynamic stress magnitudes under various loading conditions and structural parameters; and draw conclusions leading to insights into sound structural designs.