in metric tonnes, the measured volume displacement of a ship at a load draught condition multiplied by the relative water density at departure reduced by the ship’s lightweight and by the weight of the fuel on board determined at the departure of the laden voyage concerned

in metric tonnes, the measured volume displacement of a ship at a load draught condition multiplied by the relative water density at departure reduced by the ship's lightweight and by the weight of the fuel on board determined at the departure of the laden voyage concerned