or morning nautical twilight, begins when the Sun lies 12° below the eastern horizon. The term nautical arises because long ago, sailors out at sea depended on stars for navigation. Evening ...

According to the NWS, its name describes its use in navigation at sea. During nautical twilight, wrote the NWS, sailors could both see the horizon and pick out recognizable stars at the same time ...

Sunrise and sunset are defined as the moment when the upper limb of the sun breaks above or disappears below the sea-level horizon. The precise moment of civil, nautical and astronomical twilight ...

Then comes nautical twilight, which ends when the center of the sun is 12 degrees below the horizon and a seaman no longer discerns the break between the western sea and the sky. Finally ...

When the sun drops down to 12 degrees below the horizon, it marks the end of nautical twilight, when a sea horizon becomes difficult to discern. In fact, at the end of nautical twilight most ...

And that's the 30 minutes before sunrise or the 30 minutes after sunset, roughly.” When the sun is six to 12 degrees below the horizon, that’s nautical twilight, which comes before civil twilight in ...

(1) NAUTICAL astronomy is simply the application of spherical trigonometry to the problem of ascertaining the latitude and longitude at sea by observations of the heavenly bodies; as also the ...