Airdraft is defined as the distance from which reference point to the top of the ship?

Airdraft is defined as the distance from which reference point to the top of the ship?

• A. Waterline
• B. Keel
• C. Deck line
• D. Mast tip

Answer: (A)

Airdraft is the vertical distance from the water surface to the ship’s highest point. The waterline is used as the reference because it provides a consistent baseline relative to which the vessel’s top above the water is measured. This height is what determines whether the ship can pass under bridges or other overhead obstacles. In practice, the highest point might be a mast, radar, antenna, or other superstructure, but the measurement starts at the waterline and goes up to that top point. This is different from the ship’s draught (or draft), which is the depth of the hull below the waterline, or from measurements that start at the keel or deck line.

Airdraft is the vertical distance from the water surface to the ship’s highest point. The waterline is used as the reference because it provides a consistent baseline relative to which the vessel’s top above the water is measured. This height is what determines whether the ship can pass under bridges or other overhead obstacles.

In practice, the highest point might be a mast, radar, antenna, or other superstructure, but the measurement starts at the waterline and goes up to that top point. This is different from the ship’s draught (or draft), which is the depth of the hull below the waterline, or from measurements that start at the keel or deck line.