How is the draft of a vessel calculated?

The draft of a vessel is calculated by measuring the vertical distance from the waterline to the lowest point of the hull, typically the keel. This measurement can be taken at various points along the vessel's length to determine its draft at different positions. The draft can also be estimated using the vessel's displacement and the density of the water, applying Archimedes' principle, which states that the weight of the water displaced by the submerged portion of the vessel equals the weight of the vessel itself. Additionally, draft markings on the hull can provide quick reference points for determining the vessel's current draft.