Knots are a special unit of speed used in both maritime and aviation navigation. While most people are familiar with kilometers per hour or miles per hour, knots have a unique history and remain the standard for ships and aircraft worldwide.

The story of knots begins centuries ago with the log line, a simple tool sailors used to measure a ship’s speed. A rope with evenly spaced knots was thrown overboard, and the number of knots that passed through the sailor’s hands in a set time determined the ship’s speed. This practical method gave the unit its name and became a standard for maritime navigation.

One knot equals one nautical mile per hour. Nautical miles are based on the Earth’s geometry, aligning with latitude and longitude, which makes knots ideal for long-distance navigation. This unit ensures that speed, distance, and position all match the global navigation system, whether at sea or in the air.

Modern ships and aircraft continue to use knots because the unit is consistent, practical, and internationally recognized. Pilots and mariners rely on knots for navigation, route planning, and communication. Wind speeds are also reported in knots, allowing travelers to understand environmental conditions and adjust their course safely.

Typical speeds vary depending on the type of vehicle. Cargo ships usually travel around 20–25 knots, passenger ferries can reach 30–40 knots, and commercial airliners cruise at roughly 450–500 knots. Even supersonic jets often reference knots for navigation, maintaining consistency across charts and flight plans.

From the simple log line to modern jet streams, knots have stood the test of time. They link centuries of maritime tradition with today’s high-tech navigation, providing a reliable and practical way to measure speed across the oceans and skies.