Dock Water Allowance (DWA)

Loadline draft correction for brackish water. When the ship's dock-water density lies between 1.000 and 1.025, the Summer load line may be submerged by the dock water allowance without violating ICLL.

StabilityLoadline

Inputs

Fresh Water AllowancemmFrom the FWA calculator or loadline certificate.Dock water densitykg/m³Typical harbour brackish water 1010–1020 kg/m³.

DWA: 120mm

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

\text{DWA} = \text{FWA} \cdot \frac{1025 - \rho_{dw}}{25}

Symbol	Meaning	Unit
$FWA$	Fresh water allowance	mm
$\rho_{dw}$	Dock-water density	kg/m³
$DWA$	Dock water allowance	mm

Source: IMO ICLL 1966; Derrett & Barrass Ch.8

In short

Loadline DWA for brackish water from FWA and dock water density.

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