Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Navigation Problems (Set 36)
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Question 1 of 30
At 0520 zone time on 17 March, while taking stars for a morning fix, you observe an unidentified star bearing 050°T, at an observed altitude (Ho) of 45°00.0'. Your DR position at the time of the sight is LAT 27°23.0'N, LONG 39°42.0' W. The chronometer time of the sight is 08h 22m 15s, and the chronometer error is 01m 45s fast. Your vessel is steaming on a course of 300°T at a speed of 18 knots. What star did you observe?
Browse Questions in Set 36
30 MCQs #1 At 0520 zone time on 17 March, while taking stars for a morning fix, you observe an unidentified star bearing 050°T, at an observed altitude (Ho) of 45°00.0'. Your DR position at the time of the sight is LAT 27°23.0'N, LONG 39°42.0' W. The chronometer time of the sight is 08h 22m 15s, and the chronometer error is 01m 45s fast. Your vessel is steaming on a course of 300°T at a speed of 18 knots. What star did you observe? #2 On 20 June your 0800 zone time DR position is LAT 21°02.0'N, LONG 152°50.0'E. Your vessel is on course 265°T at a speed of 15.0 knots. What is the zone time of local apparent noon (LAN)? #3 On 8 April your evening DR position is LAT 22°16' N, LONG 157°58.3' W. You observe an unidentified star bearing 246°T at an observed altitude (Ho) of 58°45.5'. The chronometer reads 05h 09m 57s, and is 01m 23s slow. What star did you observe? #4 On 8 April your evening DR position is LAT 22°16.0' N, LONG 157°58.3' W. You observe an unidentified star bearing 271°T at an observed altitude (Ho) of 44°08.2'. The chronometer reads 05h 09m 57s, and is 01m 23s slow. What star did you observe? #5 On 6 December your 0800 zone time DR position was LAT 21°48.0'N, LONG 124°30.0'E. Your vessel was steaming on course 045°T at a speed of 20.0 knots. An observation of the Sun's lower limb was made at 1012 ZT. The chronometer read 02h 10m 42s and was slow 01m 02s. The observed altitude (Ho) was 41°17.1'. LAN occurred at 1129 zone time. The observed altitude (Ho) was 44°53.7'. What was the longitude of your 1200 zone time running fix? #6 On 17 January your 0730 zone time fix gives you a position of LAT 22°26.0'S, LONG 152°17.0'E. Your vessel is steaming on a course of 116°T at a speed of 17 knots. An observation of the Sun's lower limb is made at 1015 zone time. The chronometer reads 00h 13m 23s, and the chronometer error is 01m 49s slow. The observed altitude (Ho) is 66°02.1'. LAN occurs at 1152 zone time and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) is 87°54.2'. Determine the vessel's 1200 zone time position. #7 On 8 April while taking observations for an evening fix, you observe an unidentified star bearing 250.7°T at an observed altitude of 51°44.8'. Your DR position at the time of the sight was LAT 22°16.0' N, LONG 157°58.3' W. The chronometer reads 05h 09m 57s and is 01m 23s slow. What star did you observe? #8 On 22 July your 0442 DR position is LAT 26°35.6' N, LONG 22°16.7' W. You observe an unidentified star bearing 104°T at an observed altitude (Ho) of 9°55.7'. The chronometer reads 05h 39m 03s, and is 03m 14s slow. What star did you observe? #9 On 22 May your 0437 DR position is LAT 25°18.5'N, LONG 51°18.0'W. You observe an unidentified star bearing 116°T at an observed altitude (Ho) of 11°27.8'. The chronometer reads 07h 40m 40s, and is 03m 24s fast. What star did you observe? #10 On 16 June in DR position LAT 50°57.0'S, LONG 53°03.9'W (ZD+4), you take an ex-meridian observation of Acrux at lower transit. The chronometer time of the sight is 10h 08m 18s, and the chronometer error is 02m 12s fast. The sextant altitude (hs) is 23°49.0'. The index error is 1.1' off the arc, and your height of eye is 26 feet. What is the latitude at meridian transit? #11 On 2 January you are on a course of 094°T at a speed of 20 knots. At 0430 ZT, your DR position is LAT 24°12'N, LONG 71°24'W. Determine the zone time of sunrise. #12 On 22 March your 0519 DR position is LAT 27°20.6'N, LONG 69°25.6'W. You observe an unidentified star bearing 051°T at an observed altitude (Ho) of 50°03.7'. The chronometer reads 10h 16m 47s, and is 02m 15s slow. What star did you observe? #13 On 26 September your 0830 zone time DR position is LAT 23°04.0'N, LONG 129°16.0'E. Your vessel is on course 119°T at a speed of 20.0 knots. What is the zone time of local apparent noon (LAN)? #14 On 22 June your 0424 DR position is LAT 26°18.5'N, LONG 124°18.2'W. You observe an unidentified star bearing 195°T at an observed altitude (Ho) of 03°30.7'. The chronometer reads 00h 23m 24s, and is 01m 32s slow. What star did you observe? #15 During evening twilight on 28 December a sextant altitude (hs) of the planet Venus was 29°43.2'. The height of eye was 40 feet, and the index error was 2.0' on the arc. What was the observed altitude (Ho)? #16 On 22 June your 0424 DR position is LAT 26°18.5' N, LONG 124°18.2' W. You observe an unidentified star bearing 154°T at an observed altitude (Ho) of 15°01.2'. The chronometer reads 12h 23m 24s, and is 01m 32s slow. What star did you observe? #17 On 16 June 0612 zone time, morning stars were observed. The vessel's position was LAT 27°23.0'S, LONG 56°22.0'W. The vessel is steaming at 16.0 knots on a course of 212°T. A sextant observation of the Sun's lower limb is made at 0850 zone time. The chronometer reads 00h 53m 19s, and the sextant altitude is 22°58.6'. The index error is 2.0' off the arc, and the chronometer error is 02m 43s fast. Your height of eye is 61.0 feet. What is the azimuth (Zn) of this sight using the assumed position? #18 On 29 June your 0800 zone time fix gives you a position of LAT 26°16.0'S, LONG 61°04.0'E. Your vessel is steaming a course of 079°T at a speed of 15.5 knots. An observation of the Sun's upper limb is made at 0905 zone time, and the observed altitude (Ho) is 25°20.1. The chronometer reads 05h 08m 12s, and the chronometer error is 02m 27s fast. Local apparent noon occurs at 1154 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) for this sight is 40°44.2'. Determine the vessel's 1200 zone time position. #19 At 0400 zone time on 24 June, your DR position is LAT 23°10.0'N, LONG 085°33'W. You are steering 295°T at a speed of 10.0 knots. What is the zone time of sunrise? #20 On 22 July your 1759 ZT DR position is LAT 24°50.2' S, LONG 05°16.0' E. You observe an unidentified star bearing 231°T, at an observed altitude (Ho) of 26°10.0'. The chronometer reads 06h 01m 31s and is 02m 15s fast. What star did you observe? #21 On 22 May your 0437 DR position is LAT 25°18.5'N, LONG 51°18.0'W. You observed an unidentified star bearing 233°T at an observed altitude (Ho) of 29°42.3'. The chronometer reads 07h 40m 40s, and is 03m 24s fast. What star did you observe? #22 On 24 January your 0700 zone time DR position is LAT 22°25.0'N, LONG 46°10.0'W. Your vessel is on course 110°T at a speed of 12.0 knots. What is the zone time of local apparent noon (LAN)? #23 On 6 March your 1854 zone time DR position is LAT 23°51.5' N, LONG 73°14.0' W. At that time you observe Polaris with a sextant altitude (hs) of 24°16.5'. The chronometer time of the sight is 11h 52m 40s, and the chronometer error is 01m 56s slow. The index error is 5.0' on the arc, and the height of eye is 43.5 feet (13.3 meters.) What is your latitude by Polaris? #24 On 1 July your 0515 zone time fix gives you a position of LAT 23°24.0'S, LONG 151°42.0'W. Your vessel is on course 240°T, and your speed is 10.0 knots. Local apparent noon (LAN) occurs at 1215 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 42°55.0'. What is the latitude at 1200 ZT? #25 On 22 April your 1852 DR position is LAT 23°54.5'N, LONG 117°36.8'W. You observe an unidentified star bearing 248°T at an observed altitude (Ho) of 25°00.9'. The chronometer reads 02h 54m 53s, and is 02m 51s fast. What star did you observe? #26 On 14 October your 0800 zone time (ZT) dead reckoning position is LAT 28°22.0'N, LONG 161°17.0'E. Your vessel is on course 116°T at a speed of 17.5 knots. What is the ZT of local apparent noon (LAN)? #27 On 22 April your 1852 DR position is LAT 23°54.5'N, LONG 117°36.8'W. You observe an unidentified star bearing 077°T at an observed altitude (Ho) of 18°58.7'. The chronometer reads 02h 54m 53s, and is 02m 51s fast. What star did you observe? #28 At 0327 ZT on 29 May, your DR position is LAT 25°00'N, LONG 64°15'W. You are steering 270°T at a speed of 13.6 knots. What is the zone time of sunrise? #29 On 9 November at 0426 ZT, your position was LAT 25°17.0'S, LONG 154°16.0'E. Your vessel is steaming at 14.0 knots on course 066°T. A sextant observation of the Sun's lower limb is made at 0837 ZT. The chronometer reads 10h 35m 21s, and the sextant altitude (hs) is 50°26.9'. The index error is 1.5' on the arc, and the chronometer error is 01m 48s slow. Your height of eye on the bridge is 56.0 feet. What is the observed altitude (Ho) and azimuth (Zn) of this sight using the assumed position? #30 On 22 March your 0519 DR position is LAT 27°20.6'N, LONG 69°25.6'W. You observe an unidentified star bearing 200°T at an observed altitude (Ho) of 33°05.5'. The chronometer reads 10h 16m 47s, and is 02m 15s slow. What star did you observe?
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