After World War II, a huge amount of unused ammunition, including chemical, has been dumped into the Baltic Sea and Skagerrak. In some cases, entire ships filled to the brim with ammunition were sunk. Currently, even over 75 years after the second war, the fate of most dumped ammunition is unknown, and researches often try to assess the possibility of leakage and then estimate the influence of it on the local environment. Additionally, recently, the numerical models become a very suitable tool for doing such investigations thus, in our work, we hired two models to get a comprehensive picture of potential leakage from the sunken ship D/S Falkenfels, which was fully filled by chemical munition. We assumed that the ship would be totally destroyed and that all of the loads would be in the water. As a consequence, the pollutant will be soluble in water and will contaminate the surrounding local area. As the main possible toxic agents, we considered clark I, sulphur mustard, and tabun. All of them have different physical properties, the most important of which are the solubility and degradation processes. As modelling tools, we considered the high-resolution dispersion model developed by IOPAN and the commercially available CORMIX system. All simulations have been provided until the pollutant concentration reached the lethal concentration LC50. The results provided the contaminated area and its temporal variability, which gave the trajectories of maximum solute concentration as well as distances from the source until it reached toxicological limits.