In the condition of equilibrium after flooding, what is the requirement for the final waterline?

In the context of ship stability and flooding scenarios, the requirement for the final waterline after flooding is that it must be below the lower edge of any opening for down flooding. This ensures that no additional water can enter the vessel through these openings, which are typically located along the sides of the hull and on the structure. Maintaining the waterline below the lower edge of these openings prevents the risk of further flooding, allowing the vessel to maintain stability and remain afloat after the initial flooding event.

This principle is crucial for safety; if the waterline were to rise above these openings, it would increase the potential for additional water to enter the vessel, further compromising stability and buoyancy. Thus, this requirement is a fundamental aspect of ensuring the operational safety of a vessel during flooding conditions.