The objective of this paper is to study the oil spillage process which corresponds to various tank designs. For this purpose, analytical calculations and time domain simulations were applied. Numerical simulations have been performed to verify the models. Good agreement has been found between the results obtained from the simplified analytic model and those from the CFD calculations for predicting the oil spill from different hull designs. The volume and efflux rates of oil that are based on the suggested model are comparable to those obtained by means of numerical simulations.