Abstract: In order to explore the protective effects of the elastic rubber sandwich layer coated onto a ship hull, a series of 5-kg-TNT-equivalent underwater explosion tests were conducted on a floating steel box before and after the rubber sandwich was coated onto to comprehend the dynamic performance of the protective layer. Acceleration, strain and wall pressure histories at several typical locations were monitored as the main criteria and analyzed. The super-elastic protective layer is capable of lowering both acceleration and strain peaks of hull structures effectively. The wall pressure histories near the bottom hull illustrate that the transmitted impulse during the initial fluid-structure interaction stage can be reduced by almost 50%. Shock response spectrum analysis demonstrates that the elastic protective layer performs much like a low pass filter. It is capable of moderating high-frequency components of shock responses greatly, but not very effective in reducing low-frequency components.