What aspect of the vessel is measured to determine the maximum width?

The maximum width of a vessel is referred to as the beam. This measurement is crucial because it impacts the stability and handling of the boat in various conditions. A wider beam generally provides better stability, making it less prone to capsizing, while also influencing the interior space available for passengers and gear. The beam is typically measured at the widest part of the hull and is a key factor in design and classification definitions of the vessel.

Other terms, such as freeboard, gunwale, and propeller, refer to different characteristics of a boat. Freeboard describes the distance from the waterline to the upper deck level, which affects how much water the vessel can handle without taking on water. The gunwale is the upper edge of the sides of the boat, primarily providing structural support rather than contributing to width measurements. The propeller is the component that drives the vessel through the water but is unrelated to the measurement of width.