Time – The Key to Determining Longitude

For centuries, mariners were able to determine their latitude by measuring the height of a celestial body such as a star, the sun or moon above the horizon. Knowing the time of year or the phase of the moon how to do the math, latitude could be calculated. Recognizing...

Sir Isaac Newton and the Sextant

Up until the voyages of discovery began in the late 15th Century, ship captains rarely sailed out of sight of land. Why? Even though they knew what direction they were heading, mariners were not able to accurately “fix” their position. Shipboard inertial navigation...

18th Century Navigation – Evolution of the Nautical Chart

When captains went to sea in the 18th Century, computers, accurate chronographs, satellite imagery of weather, inertial navigation systems and GPS didn’t exist. Instead, the captain had a timepiece, compass, a Davis quadrant or a sextant, a chart and his knowledge of...

Ben Franklin and the Gulph Stream

In 1513, Ponce de Leon was the first to note a current that was faster than his ships, but did neither explored it nor documented its location. What de Leon discovered is the Gulf Stream. The Gulf Stream is a warm current flowing from the Gulf of Mexico, around...