What does the 'draft' of a vessel indicate?

The draft of a vessel refers to the depth of water needed for the vessel to float without discomfort or grounding. Specifically, it measures the distance from the waterline to the lowest point of the hull, typically to the bottom of the keel. This measurement tells boaters how deep the water needs to be in order for the vessel to navigate safely without touching the bottom. Understanding the draft is crucial for selecting suitable waterways, especially in shallow areas or near obstacles.

In terms of the context of the other options, the vertical surface at the back of the hull relates more to the design of the vessel, while the maximum width of a vessel pertains to its beam. The distance from the water to the lowest point of the boat is a component of the draft measurement but does not convey the complete meaning of draft as it pertains to water depth. Therefore, understanding that the draft primarily concerns the depth of water necessary for the vessel's safe operation is essential for any boater.