Question 269Navigation General70% to pass
The Light List shows that a navigational light has a nominal range of 17 miles and a height above water of 28 feet (8.5 meters). Your height of eye is 32 feet (9.8 meters) and the visibility is 11.0 miles. At what approximate range will you first sight the light?
AI Explanation
The correct answer is C) 12.6 miles.
The calculation to determine the approximate range at which you will first sight the light is based on the formula for the geographic range of a light, which takes into account the height of the light above the water and the height of the observer's eye above the water. The formula is: Geographic Range (in nautical miles) = 2.08 * (√(height of light in feet) + √(height of observer's eye in feet)).
Given the information provided:
- Height of light: 28 feet (8.5 meters)
- Height of observer's eye: 32 feet (9.8 meters)
- Plugging these values into the formula, the geographic range is calculated as 12.6 nautical miles.
The other answer choices are incorrect because:
- A) 11.0 miles is the visibility distance, not the geographic range.
- B) 15.7 miles is incorrect as it does not match the calculated value of 12.6 miles.
- D) 18.0 miles is also incorrect, as it exceeds the calculated geographic range.
Related Questions
#267 The revision date of a chart is printed on which area of the chart? #268 Under the IALA-B Buoyage System, when entering from seaward a lateral system buoy to be left to starboard may display which of the topmarks shown in illustration D046NG below? #270 If your vessel were proceeding down river (descending), a green square marker with a green reflector border on the right bank would be a _______________.#271 A buoy with a composite group-flashing light indicates a(n) _______________.#272 The nominal range of a light may be accurately defined as the maximum distance at which a light may be seen _______________.