Question 98Navigation Problems

70% to pass

On 23 July your 1700 zone time DR position is LAT 27°29' N, LONG 129°26' W. You are on course 079°T at a speed of 20 knots. Considering their magnitude, azimuth, and altitude, which group includes the three bodies best suited for a fix at star time?

A Antares, Polaris, Altair
B Jupiter, Saturn, Polaris
C Arcturus, Jupiter, Denebola
D Spica, Sabik, Vega
AI Explanation

The correct answer is D) Spica, Sabik, Vega. The key factors in determining the best stars for a fix at this position and time are the stars' magnitude, azimuth, and altitude. Spica, Sabik, and Vega are well-suited because they have a high magnitude (brightness), are in favorable positions in the sky (azimuth), and are at a suitable altitude for an accurate celestial navigation fix. The other answer choices are not as optimal. Antares, Polaris, and Altair may not be as bright or in the right positions. Jupiter, Saturn, and Polaris would not provide an ideal three-star fix. Arcturus, Jupiter, and Denebola are also not the best combination for the given conditions.

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Official Resources
USCG Navigation Rules (COLREGS) 33 CFR Navigation Rules USCG National Maritime Center
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