On Sunday, 8 November, your ship is enroute...

Question 1 / 2066636eea28f7522a1c51b659

Question 1 of 2066636eea28f7522a1c51b659

On Sunday, 8 November, your ship is enroute from Texas City, TX, to Portland, ME. At 0632 ZT, you fix your position at LAT 27°06'N, LONG 90°36'W. When the lower limb of the Sun was two-thirds of a diameter above the visible horizon, the Sun bore 105° per standard magnetic compass. At this time the chronometer read 12h 39m 20s and is 3m 20s slow. If the variation is 3°E, determine the deviation of the standard compass.

Back

Question 1 of 20

66636eea28f7522a1c51b659

No comments yet

Be the first to share your thoughts!

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

🔍 Key Concepts

• Azimuth of the Sun by amplitude vs. by altitude – which one applies when the Sun is just above the visible horizon? • Relationship between true bearing, variation, deviation, and compass bearing (TVMDC). • How to apply a chronometer correction to get the correct UTC for entering the Nautical Almanac.

💭 Think About

• First, decide what kind of observation this is: are you using the Sun’s rising/setting point on the horizon, or its vertical angle (altitude)? How does “two‑thirds of a diameter above the visible horizon” guide you? • Work from the observed bearing on the standard compass to find the true bearing of the Sun at that instant, using sight reduction or table methods. Then relate true bearing to compass bearing using TVMDC. • Think carefully about the sign convention: if you go from true to compass through variation and deviation, in which direction (E or W) would the deviation need to be to make the compass heading match what you observed?

✅ Before You Answer

• Verify the correct UTC by applying the chronometer error (slow/fast) with the right sign before taking data from the Nautical Almanac. • Check the local zone description (ZD) for Texas City / central Gulf of Mexico on 8 November to convert between ZT and UTC correctly. • When you apply TVMDC, confirm whether you are solving for deviation = (magnetic bearing – compass bearing) or some other relation, and keep track of the E/W signs carefully.

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

Quick actions

— No credit card needed

Question 1 of 20

0.8°E

0.8°W

3.8°E

3.8°W

Loading interactive features...

Question 1 / 2066636eea28f7522a1c51b659

Question 1 of 2066636eea28f7522a1c51b659

Back

Question 1 of 20

66636eea28f7522a1c51b659

No comments yet

Be the first to share your thoughts!

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

🔍 Key Concepts

💭 Think About

✅ Before You Answer

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

Quick actions

— No credit card needed