While enroute from Cape Town to Rio a...

Question 1 of 2707066636eea28f7522a1c51b135

While enroute from Cape Town to Rio a vessel's course is 281° pgc. The variation for the locality is 24° W. The deviation is 4° E. The gyro error is 2° W. What is the true course made good?

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Question 1 of 27070

While enroute from Cape Town to Rio a vessel's course is 281° pgc. The variation for the locality is 24° W. The deviation is 4° E. The gyro error is 2° W. What is the true course made good?

🔍 Key Concepts

• Relationship between gyro course (pgc), gyro error, and true course • Difference between the True–Magnetic–Compass (T–M–C) chain using variation and deviation, and the separate Gyro–True (G–T) relationship • Sign conventions for west and east errors or corrections

💭 Think About

• Start by writing a small conversion line (like a ladder) showing G, T, M, and C. Where does gyro error fit, and do you really need variation and deviation to reach True from Gyro? • Think about what a 2° W gyro error means in plain language: is the gyro reading higher or lower than the true heading? From that, decide whether you should add or subtract the 2° to get True. • Once you decide on the correct operation with gyro error, compare the resulting true course with the answer choices. Which one matches your calculated value?

✅ Before You Answer

• Be clear whether the given 281° pgc is a gyro course, not a magnetic or standard compass course. • Confirm whether variation (24° W) and deviation (4° E) are actually needed to get from gyro to true, or if they are just extra information. • Double-check the direction of correction: for a west gyro error, are you moving the true value clockwise or counterclockwise on the compass rose relative to the gyro reading?