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Using your GPS

All GPS (Global Positioning Satellites) units work exactly the same. They obtain a fix on 3 or more satellites that are orbiting the Earth. Once the GPS has determined its location it will display the information using Latitude and Longitude numbers.

A chart plotter unit will overlay a Chart on top of the Latitude and Longitude information. This wonderful as long as it is working and the screen is large enough and bright enough to be seen in all conditions.

The Professional Captain will never rely on one data source. Most carry a simple handheld GPS will all their waypoints entered. Then it becomes a simple matter to create a route using these waypoints. Routes employ the “goto” command. A highway or large arrow will then direct you to your next waypoint. These screens are much easier to read and don’t require any interpretation by the helmsman.

The mechanics are basically the same as above. Draw each leg of your course. Enter the latitude and longitude of each end point of your leg. Finally, you can combine these waypoints into a route. It’s a very simple procedure and one that can have a big payoff in safety once conditions deteriorate.