What does "draft" refer to on a vessel?

The term "draft" on a vessel specifically refers to the depth of water required for the vessel to float without any part of its hull touching the bottom. This measurement is crucial for safe navigation, as it indicates how much water a vessel needs to avoid grounding. Understanding the draft is especially important when operating in shallow waters or navigating through channels, as it helps ensure that the vessel can move freely without risk of running aground.

In contrast, the other options focus on different aspects of a vessel's dimensions. The distance from the helm to the water pertains to the position of the helm relative to the waterline, which is not defined as the draft. Similarly, the distance from bow to stern describes the overall length of the vessel, while the height of the vessel above water refers to how tall the vessel stands above the waterline, neither of which directly relates to the concept of draft.