You are steering 163°T, and a light is...

Question 1 of 31048fy_heal_CREATE_q357_2024

You are steering 163°T, and a light is picked up dead ahead at a distance of 11 miles at 0142. You change course to pass the light 2 miles off abeam to starboard. If you are making 13 knots, what is your ETA at the position 2 miles off the light?

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Question 1 of 31048

🔍 Key Concepts

• Relative motion with a fixed navigational light (the light is a point on the earth, not another vessel) • Right triangle navigation: using the desired closest point of approach (CPA) abeam as one side of a right triangle • Time-speed-distance: $\text{Time} = \frac{\text{Distance}}{\text{Speed}}$ with proper unit conversions

💭 Think About

• Sketch a simple diagram showing your original track toward the light and the point 2 miles off abeam to starboard. How does this form a right triangle? • If your CPA (closest point of approach) to the light is 2 miles abeam, what is the distance from your present position to that abeam point along your new course? • Once you have the steaming distance, how many minutes will it take to travel that distance at 13 knots, and what time does that give when added to 0142?

✅ Before You Answer

• Make sure you are using track distance to the abeam point, not the 11-mile range to the light • Confirm that you are forming a right triangle with 2 miles as the perpendicular (abeam) distance from the light to your track • Double-check your time calculation in hours and minutes after finding distance using 13 knots (nautical miles per hour)