Knots are a unique unit of speed used in both maritime and aviation navigation. While kilometers per hour and miles per hour are familiar on land, knots have a long history and practical advantages that make them essential for ships, planes, and even weather reporting.

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 in a set amount of time indicated the ship’s speed. This practical method gave the unit its name and made it a standard for navigation.

One knot equals one nautical mile per hour. Nautical miles are slightly longer than standard miles and are based on the Earth’s latitude and longitude. This makes them ideal for plotting long-distance courses and ensures that speed and distance calculations align directly with navigation charts.

Today, knots remain the standard unit for maritime and aviation speed. Ships use knots to maintain safe cruising speeds, coordinate with ports, and adjust to environmental conditions. Cargo ships typically travel at 20–25 knots, passenger ferries at 30–40 knots, and commercial airliners cruise at roughly 450–500 knots. Even wind speeds are reported in knots, helping mariners and pilots plan routes and maintain safety.

Knots also provide consistency across international waters and airspace. Pilots, air traffic controllers, and shipping crews all rely on this unit to communicate speed clearly and accurately. By understanding knots, we gain insight into how centuries of navigation experience have shaped modern travel and why this seemingly old-fashioned unit remains practical and relevant today.

From historical log lines to modern ships and aircraft, knots continue to be a vital part of navigation, connecting the past with today’s high-tech world and helping travelers move safely across oceans and skies.