What is the approximate geographic range of Fenwick Island Light, Delaware, if your height of eye is 42 feet (12.8 meters)? Refer to "Reprints from the LIGHT LISTS AND COAST PILOTS".
• Geographic range vs. luminous range of a light • How height of eye and height of light affect visibility distance • Using the Light List table or formula for geographic range based on heights in feet or meters
• First, recall the difference between geographic range (limited by the earth’s curvature) and luminous range (limited by the light’s intensity and visibility conditions). Which one is asked for here? • Think about how to use BOTH the height of the light and your height of eye to find the maximum distance the light can be seen over the horizon. • Ask yourself: if I had the Light List table, what two numbers would I look up and then combine to get the total geographic range?
• Verify the height of Fenwick Island Light from the Light List/Coast Pilot reprint table. • Use the correct table or formula that converts height (in feet or meters) to distance to the horizon (in nautical miles). • Be sure you add the two horizon distances (one for the light’s height and one for your eye height) before comparing with the choices.
No comments yet
Be the first to share your thoughts!