Underwater explosion is one of the destructive phenomena on marine and coastal structures. Understanding the mechanism of this type of explosion can be very important and effective in investigating the effects of this type of explosion on offshore structures such as oil facilities, transmission pipelines, underwater tunnels, etc. In this study, we simulated the numerical study of the effect of underwater explosion on the ship structure. In this study, a reinforced panel with dimensions of 2 by 3 meters below the water surface is subjected to an explosive charge. In order to validate the study, a valid article in this field was selected and one of the models in the article was simulated by Abacus finite element software and its results were validated. This panel is reinforced by three longitudinal and two transverse reinforcements. The simulation results were extracted in Abacus software and by reviewing and comparing with the results of the article, it was found that the results are in good agreement with the results given in the article. After validation of the article, 6 models of panels reinforced by two materials, aluminum and steel, with two boundary conditions of simple and fully retained support, in two cases with and without cracks were investigated.