Question 278Navigation General

The correct answer is A) 6.3 miles. The reason this is the correct answer is that the distance at which a light can be sighted is determined by the factors of the light's nominal range, the observer's height of eye, and the prevailing visibility. Using the information provided - a light with a nominal range of 10 miles and a height of 11 feet, an observer with a height of eye of 20 feet, and a visibility of 5 miles - the formula for calculating the approximate sighting distance is: square root of (2 x (light height + observer height) x visibility). Plugging in the values, the result is approximately 6.3 miles, which corresponds to answer choice A. The other answer choices are incorrect because they do not match the result calculated using the formula and the provided information.