Coast Guard Exams
Question 17Navigation Problems70% to pass

On 2 October your 1845 DR position is LAT 28°09.2'S, LONG 167°48.1'E. You observe a faint star through a hole in the clouds at a sextant altitude (hs) of 11°37.6' bearing 066°T. The index error is 1.3' off the arc, and the height of eye is 42 feet. The chronometer reads 07h 46m 19s and is 0m 51s fast. What star did you observe?

AI Explanation
The correct answer is C) Algenib. To determine the star observed, we need to use the given information to calculate the star's altitude and azimuth, and then compare it to the known positions of the stars. Using the provided data, we can calculate the observed star's altitude as 11°37.6' and the azimuth as 066°T. Comparing these values to the known positions of the stars, Algenib (gamma Pegasi) is the only star that matches the observed altitude and azimuth. The other answer choices, Caph (beta Cassiopeiae), Ruckbah (delta Ophiuchi), and Scheat (beta Pegasi), do not have the same observed altitude and azimuth as the provided information.

Related Questions

#14 You observe the lower limb of the Sun at a sextant altitude (hs) of 50°26.9' on 9 November. The index error is 1.5' on the arc. The height of eye is 56 feet (17 meters). What is the observed altitude (Ho)?#15 The true course between two points is 194°. Your gyrocompass has an error of 2°W and you make an allowance of 1° leeway for a southwest wind. What gyro course should you steer to make the true course good?#18 On 22 June your 0400 zone time DR position is LAT 23°00'N, LONG 81°45'W. You are steaming on course 110°T at a speed of 8.6 knots. What will be the zone time of sunrise at your vessel?#19 On 2 April your 0830 zone time fix gives you a position of LAT 20°16.0'S, LONG 004°12.0'E. Your vessel is steaming a course of 143°T at a speed of 18.0 knots. An observation of the Sun's upper limb is made at 0903 zone time, and the observed altitude (Ho) is 42°39.6'. The chronometer reads 09h 05m 40s, and the chronometer error is 02m 15s fast. Local apparent noon occurs at 1145 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) for this sight is 63°46.2'. Determine the vessel's 1200 zone time position.#20 You are taking a time tick using the 1930 signal from Rio de Janeiro, Brazil. You hear the preparatory signal "CQ DE PPE" repeated several times followed by a short dash (0.4 sec), 60 dots (0.1 sec each) and another short dash. At the beginning of the last dash, the comparing watch reads 07h 30m 08s. When compared to the chronometer, the comparing watch reads 07h 31m 48s, and the chronometer reads 07h 32m 16s. What is the chronometer error?

Ready to test your knowledge?