The distance displayed on radar is measured in __________.

Radar systems used in maritime navigation primarily display distance in nautical miles. This measurement is particularly relevant to vessels at sea because nautical miles are based on the circumference of the Earth, making them more applicable for navigation over water. One nautical mile is equivalent to one minute of latitude, which aligns well with traditional navigation techniques that rely on coordinates expressed in degrees and minutes. This is crucial for navigators because distances in nautical miles allow for greater accuracy when plotting courses and understanding distances in relation to charts, which are also based on the principles of navigation that utilize latitude and longitude.

While statute miles, kilometers, and fathoms are units of measurement used in different contexts—statute miles are commonly used on land, kilometers are part of the metric system mainly employed outside the United States, and fathoms are used to measure water depth—none of these are the standard for radar distance at sea. Thus, the use of nautical miles on radar ensures consistency and aligns with navigation conventions and maritime laws.