What does navigational draft refer to in maritime terms?

Navigational draft in maritime terms specifically refers to the distance from the waterline to the vessel's keel. This measurement indicates how deep the vessel sits in the water, which is crucial for determining whether the vessel can safely navigate in a particular waterway. When considering factors like water depth, currents, and potential obstacles, understanding the navigational draft is essential for safe passage.

While other options mention relevant concepts in maritime navigation, they do not accurately define navigational draft. The minimum depth of water for safe vessel navigation relates to the overall waterbody rather than the vessel itself, maximum height pertains to vessel loading capacities, and average weight is not a direct factor in understanding the vessel's draft. Thus, it is critical to recognize that the correct understanding of navigational draft focuses on the vertical measurement from the waterline to the keel, directly affecting the vessel’s ability to navigate safely in varying water conditions.