What is the minimum depth required in a port to accommodate a large cargo ship?

The minimum depth required in a port to accommodate a large cargo ship is primarily determined by the vessel's draft, which refers to the vertical distance between the waterline and the bottom of the hull (keel). Large cargo ships, such as container vessels and bulk carriers, generally have considerable drafts, often exceeding 10 meters.

The choice of 15.25 meters as the answer indicates an understanding that this depth provides a sufficient margin over the average draft of large vessels, accommodating variations in tide and ensuring safe navigation. In practical terms, ports that expect to serve large cargo ships typically require depths that can safely handle the vessel's draft plus additional clearance to account for environmental factors and potential loading conditions.

Depths below this level, such as 10.5 meters, 12.0 meters, or even 20.0 meters, may either be insufficient for the largest vessels or excessive relative to what is typically required for large ships, potentially resulting in unoptimized port construction and maintenance costs. Thus, the choice of 15.25 meters reflects a balance between safety and practical operational requirements for modern large cargo ships.