Sea Navigation Practice Test

When a star is observed at your Zenith, it means that the star is directly overhead at your current position. The geographic position of the star at that moment is exactly aligned with the location of the observer. Since the Zenith is defined as the point in the sky directly above a given location, if a star is located at the Zenith, the distance from the observer to the geographic position of the star is zero nautical miles. This is because the observer is essentially at the same point as the geographical coordinates of the star at that moment in time. No distance separates the two; hence the answer of zero nautical miles is correct.