Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Navigation Problems (Set 5)
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Question 1 of 30
On 16 February your 0640 zone time (ZT) position was LAT 23°46.0'N, LONG 156°24.0'W. Your vessel was steaming on course 222°T at a speed of 18.0 knots. An observation of the Sun's lower limb was made at 0910 ZT. The chronometer read 07h 08m 06s and was slow 01m 56s. The observed altitude (Ho) was 27°15.8'. LAN occurred at 1245 ZT (ZD +10). The observed altitude (Ho) was 55°25.3'. What was the longitude of your 1245 ZT running fix?
Browse Questions in Set 5
30 MCQs #1 On 16 February your 0640 zone time (ZT) position was LAT 23°46.0'N, LONG 156°24.0'W. Your vessel was steaming on course 222°T at a speed of 18.0 knots. An observation of the Sun's lower limb was made at 0910 ZT. The chronometer read 07h 08m 06s and was slow 01m 56s. The observed altitude (Ho) was 27°15.8'. LAN occurred at 1245 ZT (ZD +10). The observed altitude (Ho) was 55°25.3'. What was the longitude of your 1245 ZT running fix? #2 On 13 September your 1830 ZT DR position was LAT 23°03'S, LONG 105°16'E when you observed a faint unidentifiable star through a hole in the clouds. The star bore 265.0°T at a sextant altitude (hs) of 62°25.4'. The chronometer read 11h 24m 39s and is 5m 08s slow. The index error is 1.0' off the arc, and the height of eye is 52 feet. What star did you observe? #3 On 19 July your 1500 ZT DR position is LAT 28°25.0'N, LONG 120°28.0'W. You are on course 233°T at a speed of 10 knots. What will be the zone time of sunset at your vessel? #4 At 1800 zone time, on 7 December, your DR position is LAT 22°48'S, LONG 91°26'W. You are steering 320°T at a speed of 14.0 knots. What is the zone time of sunset? #5 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? #6 The propeller on your vessel has a pitch of 18'09". If the observed distance for a day's run was 399.4 miles and the average RPM was 86, which statement is TRUE? #7 On 8 April your evening DR position is LAT 22°16.0' N, LONG 157°58.3' W. You observe an unidentified star bearing 238°T at an observed altitude (Ho) of 50°02.7'. The chronometer reads 05h 09m 57s, and is 01m 23s slow. What star did you observe? #8 On 22 July your 1759 DR position is LAT 24°50.2' S, LONG 05°16.0' E. You observe an unidentified star bearing 100°T at an observed altitude (Ho) of 61°48.2'. The chronometer reads 06h 01m 31s, and is 02m 15s fast. What star did you observe? #9 On 22 July your 1759 DR position is LAT 24°50.2' S, LONG 005°16.0' E. You observe an unidentified star bearing 203°T at an observed altitude (Ho) of 28°12.2'. The chronometer reads 06h 01m 31s, and is 02m 15s fast. What star did you observe? #10 You observe the lower limb of the Sun at a sextant altitude (hs) of 28°24.7' on 17 May. The index error is 1.5' off the arc. The height of eye is 86 feet (26 meters). What is the observed altitude (Ho)? #11 On 22 July your 0442 DR position is LAT 26°35.6' N, LONG 22°16.7' W. You observe an unidentified star bearing 091°T at an observed altitude (Ho) of 64°35.2'. The chronometer reads 05h 39m 03s, and is 03m 14s slow. What star did you observe? #12 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? #13 On 16 August your 1600 ZT DR position is LAT 26°17.0'N, LONG 165°17.0'E. You are on course 301°T at a speed of 15 knots. What will be the zone time of sunset at your vessel? #14 On 1 April at 0515 zone time, morning stars were observed, and the vessel's position was determined to be LAT 27°05.0'N, LONG 16°30.0'W. Your vessel is steaming at 19.0 knots on a course of 022°T. A sextant observation of the Sun's lower limb is made at 0930 zone time. The chronometer reads 10h 28m 25s, and the sextant altitude is 46°20.3'. The index error is 4.5' off the arc, and the chronometer error is 02m 15s slow. Your height of eye on the bridge is 57.0 feet. What is the azimuth (Zn) of this sight using the assumed position? #15 You observe the lower limb of the Sun at a sextant altitude (hs) of 38°07.5' on 8 August. The index error is 5.2' off the arc. The height of eye is 72 feet (22 meters). What is the observed altitude (Ho)? #16 On 23 September your 1836 DR position is LAT 25°18'S, LONG 162°36'E. You observe an unidentified star bearing 148°T at an observed altitude (Ho) of 13°32'. The chronometer reads 07h 34m 12s, and is 01m 54s slow. Which star did you observe? #17 On 17 May your 0300 ZT DR position is LAT 27°21.0'N, LONG 146°14.0'E. You are on course 107°T at a speed of 18 knots. What will be the zone time of sunrise at your vessel? #18 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? #19 On 22 March your 0519 DR position is LAT 27°20.6'N, LONG 69°25.6'W. You observe an unidentified star bearing 115°T at an observed altitude (Ho) of 54°52.8'. The chronometer reads 10h 16m 47s, and is 02m 15s slow. What star did you observe? #20 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 63°29.1' bearing 237.5°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? #21 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? #22 On 29 April your 1913 zone time DR position is LAT 22°09.0' N, LONG 56°16.0' W. At that time you observe Polaris with a sextant altitude (hs) of 22°25.8'. The chronometer time of the sight is 11h 11m 14s, and the chronometer error is 02m 18s slow. The index error is 1.5' off the arc, and the height of eye is 61.5 feet. What is your latitude by Polaris? #23 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 68°03.6' bearing 154°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? #24 On 22 June your 0424 DR position is LAT 26°18.5' N, LONG 124°18.2' W. You observe an unidentified star bearing 249°T at an observed altitude (Ho) of 52°50.7'. The chronometer reads 00h 23m 24s, and is 01m 32s slow. What star did you observe? #25 On 22 May your 0437 DR position is LAT 25°18.5' N, LONG 51°18.0' W. You observe an unidentified star bearing 142°T at an observed altitude (Ho) of 23°10.2'. The chronometer reads 07h 40m 40s, and is 03m 24s fast. What star did you observe? #26 On 16 November your 0800 ZT DR position is LAT 25°11.0'N, LONG 117°41.0'W. Your vessel is on a course of 252°T at a speed of 14.5 knots. What is the ZT of local apparent noon (LAN)? #27 At 0800 ZT on 29 June your DR position is LAT 26°00.0'N, LONG 75°29.5'W. Given a chronometer time of 01h 00m 00s, determine the computed altitude (Hc) of the Sun for the assumed position nearest to the above given latitude and longitude. #28 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? #29 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? #30 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)?
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