What is the term for the shortest distance from the waterline to the top of a vessel's sides or transom?

The correct term for the shortest distance from the waterline to the top of a vessel's sides or transom is known as freeboard. Freeboard is an important aspect of a boat's design, as it indicates the height of the vessel's hull above the waterline and contributes to the boat’s safety and stability. Adequate freeboard is essential because it helps prevent water from washing over the sides of the vessel, particularly in rough weather or sea conditions, thus maintaining the vessel's buoyancy and structural integrity.

In contrast, the other terms have distinct definitions. Draft refers to the vertical distance between the waterline and the bottom of the hull (the keel) and is crucial for determining how deep a vessel sits in the water. LOA, or length overall, measures the total length of the vessel from the bow to the stern, and beam refers to the width of the vessel at its widest point. Each of these terms provides important information about a vessel's dimensions and capabilities, but they are not applicable when describing the height of the sides above the waterline.