Sailing the Caribbean Ocean in the Riviera Maya with clear turquoise waters and blue skies you may think at some point... "I wonder how fast we are moving" It is a question our Captain will be happy to answer if you visit him at the helm, he will tell you how fast the beautiful 65 foot catamaran is cruising in knots.
When the nautical mile (1.852 kilometers) was introduced in the 15th century, sailors had a handy standard against which to measure speed and created out of necessity, the chip log, the world’s first maritime speedometer. The brave Sailors used materials they had on hand, A wedge-shaped piece of wood, a small glass timer, and a really long rope. However not any rope! Based on the length of the nautical mile, knots were tied along the log line at intervals of 14.4 meters. One end was secured to the ship’s stern and the other was attached to the wooden board, which was dropped into the water.
As one sailor watched the sand empty through the 30-second glass, his shipmate held the line as it played out behind the ship and counted the knots as they passed between his fingers. Dividing that 14.4 meters by 30 seconds told them that one knot equaled 1.85166 kilometers per hour, or one nautical mile. By performing the calculation using the actual number of knots that unspooled, the sailors were able to measure the ship’s speed.
Today, maritime speed is determined by ultrasonic sensors or Doppler measurement, and the 30-second divisor in the rate equation has been replaced by 28. But the instrument for measuring a vessel’s speed is still called a log, and marine and aeronautical distances are still measured in nautical miles. So do not worry... While you are chilling out catching some rays, enjoying a cocktail or the beautiful view you can be rest assured you will not have to count the knots!!