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Load Line - Seasonal Marks Check

Load-line seasonal mark (S, W, T, F, TF, WNA) applicable for the ship's voyage - a function of Load Line Zone and date.

Load lineSeasonalZones
Applicable mark
T
Formula, assumptions, and limits

Zones defined in Load Line Convention 1966 Annex II - seasonal boundaries vary by latitude and month. Tropical mark allows deeper loading than Summer by 1/48 × summer draft. WNA for ships ≤ 100 m L in winter North Atlantic.

Symbol legend

SymbolMeaningUnitSource
Load line zone - Load Line Convention 1966 Annex II