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Supply Chain Glossary
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Draft (Draught)

What is a Ship's Draft?

A ship’s draft (also spelled draught) is the vertical distance between the waterline and the lowest point of the ship’s hull (usually the keel). It measures how deep a ship sits in the water and determines the minimum depth of water a vessel can safely navigate. The draft is an essential measurement for ensuring a ship can enter certain ports, harbors, and canals without grounding or hitting the seabed.

What is the Typical Draft of a Cargo Vessel?

The typical draft of a cargo vessel can vary depending on the ship's size and type. For example, container ships may have drafts ranging from 10 to 16 meters (33 to 52 feet), while bulk carriers or tankers can have deeper drafts of up to 20 meters (66 feet) or more. Larger vessels generally have deeper drafts, requiring deeper water channels, whereas smaller ships may have a draft of less than 10 meters.

How to Read Draft Marks on a Ship

Draft marks are vertical numbers displayed on the side of a ship’s hull near the bow and stern, showing the ship's depth in the water. These numbers, usually in meters or feet, are spaced at regular intervals and help monitor the ship’s draft. To read them, you observe the lowest visible number at the waterline. The draft marks are essential for ensuring the ship is loaded within its safe operational limits, preventing overloading and maintaining stability.