The Seminar is designed to be done in one sitting of about 90 minutes. Before electronic navigation aids like GPS and electronic chartplotters came along, coastal sailors plotted fixes by using natural and man-made references, such as lighthouses, buoys, church steeples, radio/TV towers, and so on, that were plotted in their exact locations on paper navigation charts. They did this by taking quick-succession bearings on two or more of these objects, thus producing lines of position (LOPs) that crossed each other at some point. When these LOPs were plotted on the paper chart, the sailor could see the fix, indicating the boat’s position. This process is called getting a terrestrial fix. However, if the sailor is in the middle of an ocean, there are no lighthouses or church steeples. There is a solution however, and as the Friendly Giant used to say, “Look up … way up,” and there are all those heavenly bodies, “lighthouses in the sky.”
