Which of the following indicates the depth of water required for a ship to float?

The draft of the ship is the measurement that indicates the depth of water required for a ship to float. It refers to the vertical distance between the waterline and the bottom of the hull (keel). This measurement is crucial because it determines how deep a vessel sits in the water and, consequently, how much water is needed for the ship to remain afloat without touching the seabed or running aground.

Understanding the draft is essential for navigation, as it helps in avoiding shallow areas and ensuring safe passage through varying water depths. In contrast, the height of the mast pertains to the vertical clearance necessary to ensure a ship can pass under bridges or other overhead obstacles, while the beam (width) of the ship indicates stability and capacity but does not affect its buoyancy in terms of needed water depth. Similarly, the length of the ship contributes to overall vessel design and performance but does not relate directly to the depth of water required for floating. Therefore, draft is the most relevant measure regarding water depth for safe navigation.