Knots vs. MPH has confounded new boaters, so we put together a short explainer

With so many opportunities for enjoyment out on the water, whether you’re enjoying a day on the Bay, lake, or river, precise navigation is crucial, and understanding the components of how to navigate is especially critical. Many first-time boaters use Argo, so we thought we would explain knots vs. MPH, since knots are the fundamental metric used on the water. Knots are a unit of speed that is often confused with miles per hour. In this blog, we will unravel the difference between the two, explore the significance of nautical miles, and delve into the fascinating history behind the use of knots in maritime traditions.

History of Knots in Maritime Tradition

To understand knots, we first must look at the history of the metric. The use of knots in maritime navigation dates back centuries, with its roots deeply embedded in the maritime traditions of the past. The term “knot” itself reflects this history, as sailors historically measured their ship’s speed by tossing a pie slice-shaped log with a rope attached into the water and counting the number of knots that passed through their hands in a specific time frame.

The process involved tying equally spaced knots on the log line, each representing a certain speed increment. Sailors would then cast the log overboard, allowing it to trail behind the moving ship. By timing how quickly the knots passed through their hands, sailors could calculate the vessel’s speed in knots.

The log and line method evolved over time, and today’s technology has replaced it with more accurate instruments, such as the log sensor or the knotmeter. However, the term “knot” has persisted, paying homage to the historical methods that laid the foundation for modern nautical navigation.

Understanding Knots and Miles Per Hour

When it comes to measuring speed at sea, two terms often come into play: knots and miles per hour (MPH). While miles per hour is a familiar unit of speed used in various contexts, well-known to us when we drive our cars each day, knots are specific to maritime navigation. The key distinction lies in their origins and applications.

Miles per hour is a standard unit of speed used globally and is calculated based on the distance traveled over one hour. On the other hand, knots refer to nautical miles per hour. A nautical mile is a unit of measurement used in navigation and is based on the circumference of the Earth. One nautical mile is equivalent to one minute of latitude, making it a practical choice for maritime distances.

Nautical Miles vs. Statute Miles

To fully comprehend the concept of knots, one must grasp the distinction between nautical miles and statute miles. A statute mile is the standard mile used in most land-based measurements, equal to 5,280 feet. In contrast, a nautical mile is slightly longer, measuring 6,076 feet or one minute of latitude.

The use of nautical miles in maritime navigation is advantageous because it allows for more precise and straightforward calculations. Latitude coordinates on nautical charts are conveniently expressed in minutes and seconds, aligning seamlessly with the nautical mile as a unit of distance.

Significance of Knots in Contemporary Navigation

In the modern era, the use of knots in maritime navigation remains essential. Sailors, captains, and maritime enthusiasts worldwide rely on knots as a standard unit of speed at sea. The compatibility of nautical miles and knots simplifies navigation, providing a practical and efficient system for measuring distances and speeds on the water.


In the intricate world of maritime navigation, the distinction between knots vs. MPH holds paramount importance. Knots, deeply rooted in maritime history, are a testament to the ingenuity of sailors who devised methods to measure speed at sea. As technology advances, the tradition of using knots persists, bridging the gap between the past and the present in the ever-evolving world of maritime navigation. So, the next time you find yourself navigating the open waters, remember that knots are more than just a unit of speed—they embody a rich maritime legacy that continues to guide boaters on the water.

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