When measuring speed in nautical contexts, it is expressed in what unit?

In nautical contexts, speed is expressed in knots. A knot is defined as one nautical mile per hour, which makes it the standard measurement for maritime and aviation navigation. This unit is particularly relevant on the water since distances in navigation are often measured in nautical miles, which correspond to the curvature of the Earth.

The use of knots provides a clear indicator of an object's speed in relation to the earth's surface over water, accounting for factors like currents and wind. This consistency in measurement is essential for calculations involving navigation, ensuring sailors and aviators effectively coordinate routes and travel times.

Using kilometers or miles per hour, while common in terrestrial contexts, does not align with the specific needs of nautical navigation, as the nautical mile is based on the geometry of Earth's surface. Therefore, for maritime activities, the knot is the correct and most useful metric for speed.