The vertical distance between the keel and the waterline, determining the minimum water depth needed for safe navigation.
In practice
The chief mate reads the draught marks — graduated scales welded or painted on the hull at bow, stern, and midships — before and after loading or discharging operations and enters the figures in the cargo log and stability booklet. Draught surveys are a recognised commercial method for calculating the quantity of bulk cargo loaded or discharged by comparing draught-derived displacement figures before and after cargo operations. Under SOLAS V, the master must have access to draught and trim information relevant to safe navigation, particularly in areas with restricted depths or UKC requirements imposed by port approach channels.
Regulatory detail & full definition
Draft (or draught) is the vertical distance between the ship's keel — or more precisely the lowest point of the hull — and the waterline. Draught is measured at the bow (forward draught), at the stern (aft draught), and amidships to determine trim and to calculate the vessel's displacement. Accurate draught reading is critical for ensuring compliance with load line regulations, confirming sufficient underkeel clearance in shallow water, and verifying that the loading computer's stability and stress calculations are correct.
The chief mate reads the draught marks — graduated scales welded or painted on the hull at bow, stern, and midships — before and after loading or discharging operations and enters the figures in the cargo log and stability booklet. Draught surveys are a recognised commercial method for calculating the quantity of bulk cargo loaded or discharged by comparing draught-derived displacement figures before and after cargo operations. Under SOLAS V, the master must have access to draught and trim information relevant to safe navigation, particularly in areas with restricted depths or UKC requirements imposed by port approach channels.