In the design of floating structures against under water explosion, it is important to predict the expected damage in different explosion scenarios with a reasonable accuracy. Two dimensional computer codes capable of accurately simulating such explosion events are available. Actual explosion events are, however, three dimensional. Recently, a three dimensional code, MSC/DYTRAN, capable of such three dimensional simulation became available. The authors have established a procedure to accurately simulate realistic three dimensional explosion events using the computer code. Experimental verification of this procedure is also carried out. In this paper, under water explosion experiments are described, numerical simulation of one of these experiments is reported, and a comparison of simulation results to experimental results is also presented.