At any time whether during combat or non-combat, naval ships are susceptible to damage. During combat, navy ships are susceptible to suffer damage to a particular degree on its armament, hull or even its technical equipment. The damages are of specific nature and occur at specific places on the ship. For example, during combat, a navy ship can suffer damage from torpedoes and mine explosions, impact resulting from artillery shells, missiles or airborne bombs or even due to effects from weapons of mass destruction. This damage results in flooding of the affected areas. During the ship's operation at sea a significant threat to its safety is fire. Although fire rarely causes the ship to sink, the damage that it leaves is usually very serious, though the extent of the damage depends on the level of crew training in the area of emergency response. The main extinguishing agent used on ships is usually sea water, which in large quantities poses a threat to the safety of the ship. It affects changes in the stability and position of the ship. Determination of these changes is the basis for the sub-capacity calculations related to the operation of a damaged ship. Therefore, the main focus of the work was to determine the impact of flooding of high-located compartments on the safety of a ship. The results of the calculations presented in the paper include information about the amount of water in the range causing deterioration of the stability of the ship.