What term describes the depth of water needed to float a vessel?

The term that describes the depth of water needed to float a vessel is referred to as "draft." Draft is a critical concept in boating, as it measures the vertical distance between the waterline and the bottom of the keel or hull. This measurement is essential for determining whether a vessel can safely navigate certain waterways without running aground.

Understanding the draft of a boat helps operators to know the minimum water depth required for safe passage, particularly in shallow areas or when entering harbors or docks. A vessel with a greater draft requires deeper water to avoid potential damage, while vessels with a shallower draft can operate in less water.

Displacement refers to the weight of water that a vessel displaces when it is floating, which is related to the vessel's overall buoyancy and stability but does not specifically address the depth requirement. The keel is the structural component along the bottom of a ship that helps provide stability and may play a role in determining the draft, but it itself does not describe the depth needed to float. Lastly, a displacement hull is a type of hull design that displaces water as it moves through it, impacting performance characteristics but not directly defining the measure of water depth needed for floating.