During which phase of twilight can navigation be performed using visible stars?

• A. Civil Twilight
• B. Nautical Twilight
• C. Sunrise
• D. Sunset

Answer: (B)

Nautical Twilight is the phase during which navigation can be effectively performed using visible stars. During this period, the sky is dark enough that sailors can see stars for navigation, yet there is still some light on the horizon, which helps differentiate between sea and sky. This stage typically occurs when the sun is between 6 and 12 degrees below the horizon.

In this phase, mariners can take their bearings using a sextant and rely on celestial bodies for navigation, as the visibility is sufficient to identify stars while still being dark enough for them to be visible against the backdrop of the sky. This capability is essential for maritime navigation, especially when out of sight of land or in situations where visual aids are limited.