At 0630 you increase speed to 12.0 knots. At...

At 0630 you increase speed to 12.0 knots. At...

Question 1 of 2707066636eea28f7522a1c51a87b

At 0630 you increase speed to 12.0 knots. At 0645 Race Rock Light bears 294°pgc. At 0700 Race Rock Light bears 293°pgc. Based on this, what action should you take?

Question 1 of 27070

Q

At 0630 you increase speed to 12.0 knots. At 0645 Race Rock Light bears 294°pgc. At 0700 Race Rock Light bears 293°pgc. Based on this, what action should you take?

🔍 Key Concepts

• Relative bearing change and what it tells you about risk of collision with a fixed object • Effect of increasing speed on your track relative to a nearby point of land or light • How to interpret a bearing that is changing slightly over time: is the object drawing ahead, abeam, or abaft?

💭 Think About

• Compare the two position lines: is the light’s relative bearing moving more toward your bow or more toward your stern as time passes? What does that say about whether you will pass ahead of or astern of it? • Ask yourself: if the bearing to a fixed object is only changing very slightly over 15 minutes at 12 knots, is your CPA (closest point of approach) likely to be large or small? • Think about which way you would need to swing your ship’s head to make the bearing change faster away from a potential collision situation with that light.

✅ Before You Answer

• Verify whether the bearing is increasing or decreasing with time, and by how much. • Consider the relative motion diagram: draw your course and two lines of bearing from the light and see on which side of the light your track passes. • Check which type of maneuver (course change vs. speed change) most effectively increases your closest point of approach (CPA) to a fixed danger.