Luminous Range is defined as what?

• A. Distance to horizon
• B. Distance the light would be seen at 10 nm
• C. Distance based on Secret conditions
• D. Max distance at which light can be seen under existing visibility conditions

Answer: (D)

Luminous range is the maximum distance at which a light can be seen under the prevailing meteorological visibility. It reflects how far the light can be observed given the current weather and the light’s brightness, independent of how high the observer is or how far the horizon is. This is why it’s about visibility conditions rather than just geometry.

The other ideas don’t fit: distance to the horizon is geographic range, which depends on height and Earth’s curvature; the reference to 10 nautical miles relates to nominal range (visibility in a standard 10 nm atmosphere), not the actual current conditions; and “secret conditions” isn’t a nautical term.