Research on damage stability and unsinkability is a valuable source of knowledge of behaving a ship while flooding its compartments. In the paper, a short description of accidents and damages of Polish warships is presented. The time when compartment is flooded (tf) and stability parameters are one of the key elements which have influence on a rescue action. The knowledge of the time mentioned is very important for a commanding officer making decisions while fighting for survival of the ship. To provide the information about the time tf a new method was designed. The method was tested experimentally and results of the tests are presented in the paper. In the experiments, the flooding process of compartments in a ship of the type 888 was simulated. The next part of research was carried out on the laboratory stand bed, where the flooding time of damaged compartment of warship model was measured. The results of the experiments can be a base to define general rules to make proper decisions during the process of damage control