Question 72Navigation General70% to pass
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?
AI Explanation
The correct answer is B) 10.0 miles.
The formula to calculate the distance at which a light can be sighted is:
Distance to Horizon (in nautical miles) = 1.17 x √(height of eye in feet) + 1.17 x √(height of light in feet)
Plugging in the values given:
Distance to Horizon = 1.17 x √(20 ft) + 1.17 x √(42 ft) = 5.2 miles + 4.8 miles = 10.0 miles
The other options are incorrect because:
A) 20.1 miles is too far, as the visibility is only 6 miles.
C) 7.6 miles is too close, as the calculated distance is 10.0 miles.
D) 6.0 miles is too close, as the calculated distance is 10.0 miles.
Related Questions
#70 The Light List indicates that a light has a nominal range of 13 miles and is 36 feet high. If the visibility is 17 miles and your height of eye is 25 feet, at what approximate distance will you sight the light? #71 You sight a buoy fitted with a double-sphere topmark. If sighted at night, this buoy would show a _______________.#73 Coast Pilots and navigational charts are kept corrected and up-to-date by using the _______________.#74 You are in a buoyed channel at night and pass a lighted buoy with an irregular characteristic. You should report this to the _______________.#75 When a light is first seen on the horizon it will disappear again if the height of eye is immediately lowered several feet. When the eye is raised to its former height the light will again be visible. This process is called _______________.