On 22 October in DR position LAT 21° 51.0'...

Study

Question 1 of 2066636eea28f7522a1c51ad1d

On 22 October in DR position LAT 21° 51.0' S, LONG 76° 24.0' E, you observe an amplitude of the Sun. The Sun's center is on the visible horizon and bears 256° psc. The chronometer reads 01h 01m 25s and is 01m 15s fast. Variation for the area is 2° E. What is the deviation of the standard magnetic compass?

Back

Question 1 of 20

66636eea28f7522a1c51ad1d

No comments yet

Be the first to share your thoughts!

If the question has a related picture, it will appear here.

🔍 Key Concepts

• Amplitude of the Sun and how it relates to true bearing at the horizon • Steps to convert a compass bearing to a true bearing using deviation and variation • Using chronometer time and longitude to obtain the Sun’s declination from the Nautical Almanac (conceptual step, no tables needed here)

💭 Think About

• From the DR latitude and the Sun’s declination at the time of observation, what is the formula that gives you the Sun’s true amplitude (true bearing when on the visible horizon)? • Once you have the true bearing, how do you work backward from: Compass → Magnetic → True, using the given variation, to isolate the unknown deviation? • Pay attention to the sign convention: is easterly variation/deviation added or subtracted when going from true to magnetic to compass?

✅ Before You Answer

• Confirm you are using the correct latitude (S) and declination sign (N/S) when applying the amplitude formula—this affects whether you add or subtract from due east/west. • Carefully apply chronometer error (fast/slow) before using the time to conceptually get declination—don’t skip the correction step. • When solving for deviation, double-check the sequence True ↔ Magnetic ↔ Compass and the sign of variation (2° E) so you don’t reverse the correction.

👋 Hi! I'm Genie, your AI study assistant. How can I help you with this question?

Quick actions

— No credit card needed