Distance at sea matches the geometry of the Earth. A nautical mile is a unit of distance equal to exactly 1,852 meters, approximately one minute of latitude.

The unit links distance directly to angular measurement on the globe, which is why it remains standard for navigation and aviation. Speed in knots is one nautical mile per hour. Charts are scaled in nautical miles, and radar ranges are commonly displayed in the same unit.

Confusion between nautical miles and statute miles or kilometers can produce serious errors in fuel planning and position. Professional navigators work consistently in nautical miles and knots so that time, speed, and distance stay coherent.

• Distance unit of 1,852 meters
• Approximately one minute of latitude
• Standard for marine and air navigation
• Paired with knots for speed