The Light List indicates that a light has a...

Question 1 of 2707066636ee928f7522a1c519a91

The Light List indicates that a light has a nominal range of 14 miles and is 42 feet high (12.8 meters). If the visibility is 6 miles and your height of eye is 20 feet (6.1 meters), at what approximate distance will you sight the light?

Back

Question 1 of 27070

🔍 Key Concepts

• Luminous range vs. geographic range and which one is limited by visibility • How to compute geographic range of visibility using height of light and height of eye (sum of their individual ranges) • Effect of meteorological visibility (in miles) when it is less than the nominal range

💭 Think About

• First, decide whether the nominal range (14 miles) or the visibility (6 miles) will limit how far away you can see the light in this situation. • Calculate the geographic range based on the 42 ft light height and 20 ft height of eye, then compare that distance to the visibility limitation. • Ask yourself: if the geographic range is greater than what the weather allows you to see, which value actually controls the maximum distance of sighting?

✅ Before You Answer

• Confirm which range is reduced when visibility is less than the nominal range of the light. • Verify that your calculated geographic range is reasonable for a light and eye only a few tens of feet above the water. • Before choosing, compare both your geographic range and the 6-mile visibility to see which is the controlling factor.