Damaged Waterline

Equilibrium waterline of a ship after damage flooding has reached steady state. The damaged waterline must remain below the bulkhead deck (or for some ship types the margin line) for SOLAS II-1 compliance, and intermediate flooding stages must satisfy progressive flooding criteria. The shape of the damaged waterline depends on the assumed damage extent (length, depth, vertical extent) per SOLAS Reg. 6, the permeability of the flooded spaces, and the trim and heel that result. Damaged stability calculations are required for the worst-case damage scenarios.