Question 420Navigation General70% to pass
The Light List indicates that a light has a nominal range of 14 miles and is 26 feet high. If the visibility is 4 miles and your height of eye is 20 feet, at what approximate distance will you sight the light?
AI Explanation
The correct answer is A) 7.5 miles.
The distance at which the light will be sighted can be calculated using the formula for the geographic range of a light, which is: D = 2.07 x (√h + √H), where D is the geographic range in nautical miles, h is the height of eye in feet, and H is the height of the light above the water in feet.
Given the information provided:
- Nominal range of light: 14 miles
- Height of light: 26 feet
- Visibility: 4 miles
- Height of eye: 20 feet
Plugging these values into the formula, we get:
D = 2.07 x (√20 + √26) = 2.07 x (4.47 + 5.10) = 2.07 x 9.57 = 19.8 miles
However, the visibility is limited to 4 miles, so the actual distance at which the light will be sighted is 7.5 miles, which is the correct answer.
The other options are incorrect because they do not accurately reflect the calculated distance based on the given information.
Related Questions
#418 The Light List shows that a navigational light has a nominal range of 6 miles and a height above water of 18 feet (5.5 meters). Your height of eye is 47 feet (14.3 meters) and the visibility is 1.5 miles. At what approximate range will you first sight the light? #419 The Light List indicates that a light has a nominal range of 14 miles and is 26 feet high. If the visibility is 14 miles and your height of eye is 20 feet, at which approximate distance will you sight the light? #421 The Light List indicates that a light has a nominal range of 18 miles and is 38 feet high. If the visibility is 6 miles and your height of eye is 15 feet, at which distance will you sight the light? #422 The Light List indicates that a light has a nominal range of 8 miles and is 48 feet(14.6 meters) high. If the visibility is 6 miles and your height of eye is 35 feet(10.7 meters), at what approximate distance will you sight the light? #423 Your height of eye is 40 feet (12.2 meters). What is the approximate geographical distance at which Ambrose Light, NY, could be visible? Refer to "Reprints from the LIGHT LISTS AND COAST PILOTS".