🔍 Key Concepts

• Luminous range vs geographic range of a light and which one limits visibility when visibility is restricted • How to use your vessel’s course, speed, and position at 0730 to find your changing distance from Horton Point Light • Interpreting a Light List or charted range value together with a stated visibility (e.g., 5.5 miles)

💭 Think About

• At 0730, how far are you from Horton Point Light based on your DR/plot, and is that distance less than or greater than the maximum visible range given 5.5 miles visibility? • Are you moving toward or away from the light at 0730, and at what rate is your distance from the light changing (relative speed along the line of sight)? • Once you know the distance at which the light will disappear, how many minutes from 0730 does it take you to reach that distance at your current speed and track?

✅ Before You Answer

• Confirm the maximum distance you can see the light in 5.5-mile visibility (consider nominal range vs geographic range and pick the smaller). • Verify your distance from the light at 0730 on the chart/plot before doing any time calculation. • Double‑check the vessel’s speed and direction you use to compute the time to go from the 0730 distance to the “disappearance” distance.