What information does GPS provide for nautical navigation?

What information does GPS provide for nautical navigation?

• A. Weather forecasts and tide tables.
• B. Precise position, course, and speed data to determine the vessel’s track.
• C. Depth readings and current speed.
• D. Magnetic variation values only.

Answer: (B)

GPS provides precise position, course over ground, and speed over ground, which you use to determine the vessel’s track. Position fixes give your exact spot on the globe (latitude and longitude). Course over ground is the direction you’re actually moving relative to true north, and speed over ground is how fast you’re traveling over the ground. By linking successive position fixes over time, you can map the path you’ve taken on the chart—the track.

Think of GPS as your continuous position and motion log. It doesn’t supply weather forecasts or tide tables, which come from meteorological and tidal sources. It doesn’t provide depth readings from a depth sounder, current speed from a log, or magnetic variation values from charts and a compass. Those come from their respective instruments and models.