Damaged Waterline
Equilibrium waterline after damage flooding; must remain below margin line / bulkhead deck for SOLAS compliance.
In practice
Visualised on the loading-instrument damage-condition output. Master verifies the damaged waterline does not exceed margin line for any worst-case damage scenario.
Regulatory detail & full definition
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.
Authoritative source: SOLAS Chapter II-1 (Construction — Subdivision and stability) ↗
Related
Source: SOLAS II-1
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