How dark is it during nautical twilight?
Quick Answer: During nautical twilight, the sky is dark enough that the horizon is still visible at sea, but overall it is quite dim. You can see outlines of objects but fine details are hard to make out. It’s darker than civil twilight but not fully night yet.
Nautical twilight happens when the sun is between 6 and 12 degrees below the horizon. This means the sky loses most of its brightness, making it tricky to see colors or small details clearly. The horizon line remains visible, which is why sailors use this time for navigation.
It’s a kind of in-between light, where you still get some natural illumination but it’s subtle. The darkness deepens as the sun moves further down, heading toward astronomical twilight and full night.