🔍 Key Concepts

• Geographic range vs. luminous range of a light • Effect of meteorological visibility on how far a light can be seen • Use of nominal range diagrams or visibility tables in light lists

💭 Think About

• Think about whether the question is asking how far away the light CAN first be seen, or at what distance it will DISAPPEAR as you go farther away. • Consider how a visibility of 3 miles limits the luminous range of a light, even if the geographic range is much greater. • Ask yourself: in 3‑mile visibility, can any light be seen farther than 3 miles, regardless of its power?

✅ Before You Answer

• Identify whether the controlling factor is visibility or the charted/nominal range of Chesapeake Light. • Compare each answer choice to the stated 3‑mile visibility and see which ones are obviously inconsistent. • Verify how exam questions usually treat “visibility X miles” when asking about when a light becomes obscured.