Visibility is exceptionally clear. At...

🔍 Key Concepts

• Geographic range of visibility of a light depends on the light’s height and the observer’s height of eye, not just how ‘clear’ the weather is • Use the distance to the horizon formula to estimate how far away you can see an object of known height • Check typical nominal range vs geographic range on Light Lists and charts

💭 Think About

• Think about how you would calculate the maximum distance you could see a light if you know both your height of eye on the vessel and the charted height of Chesapeake Light • Ask yourself: in exceptionally clear visibility, which limit usually controls how far you can see—nominal range (brightness) or geographic range (curvature of the earth)? • Consider which option best matches a realistic geographic range for an offshore light structure of Chesapeake Light’s approximate height

✅ Before You Answer

• Confirm you are using geographic range, not luminous/nominal range, for ‘exceptionally clear’ conditions • Make sure you conceptually add the observer’s horizon distance and the light’s horizon distance when estimating maximum visibility • Eliminate choices that seem too short or too long compared with a typical light structure visible just over the horizon from an offshore vessel’s bridge

Visibility is exceptionally clear. At approximately what distance did Chesapeake Light become visible?

19.2 miles

21.0 miles

22.7 miles

24.0 miles

🔍 Key Concepts

💭 Think About

✅ Before You Answer