What does "knot" measure in maritime terms?

In maritime terminology, a "knot" specifically refers to the speed of a vessel, with one knot being equivalent to one nautical mile per hour. This measurement is commonly used in navigation and marine operations, as it provides a standardized unit to measure how fast a boat or ship is moving through the water. Nautical miles are based on the circumference of the Earth and are used instead of statute miles in maritime contexts due to their relevance to navigation and the Earth's geometry. Thus, the distinction that a knot relates to the vessel's speed underscores its importance in safe navigation, ensuring that mariners can effectively manage their courses and timings at sea.