Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Navigation Problems (Set 8)
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Question 1 of 30
On 13 October your 0515 zone time (ZT) fix gives you a position of LAT 26°53.0'N, LONG 90°05.0'W. Your vessel is on course 068°T, and your speed is 7.8 knots. Local apparent noon (LAN) occurs at 1145 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 54°51.5'. What is the calculated latitude at LAN?
Browse Questions in Set 8
30 MCQs #1 On 13 October your 0515 zone time (ZT) fix gives you a position of LAT 26°53.0'N, LONG 90°05.0'W. Your vessel is on course 068°T, and your speed is 7.8 knots. Local apparent noon (LAN) occurs at 1145 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 54°51.5'. What is the calculated latitude at LAN? #2 On 1 July your 0515 ZT fix gives you a position of LAT 24°36.0'S, LONG 151°42.0'W. Your vessel is on course 300°T, and your speed is 10.0 knots. Local apparent noon (LAN) occurs at 1215 ZT, 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 calculated latitude at LAN? #3 On 7 November your 0830 zone time fix gives you a position of LAT 27°36.0'N, LONG 162°19.0'W. Your vessel is on course 289°T and your speed is 19.0 knots. Local apparent noon (LAN) occurs at 1138 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 45°35.0'. What is the latitude at 1200 ZT? #4 On 22 May at 0440 ZT, your vessel's DR position is LAT 23°24' N, LONG 110°24' W. At approximately this time, you obtain a sextant altitude (hs) of Polaris reading 23°40.9' with an index error of 1.6' on the arc. Your chronometer reads 11h 42m 14s, and is 2m 36s fast. What is your latitude by Polaris, given a height of eye of 24 feet? #5 On 13 October your 0515 zone time fix gives you a position of LAT 26°53.0'N, LONG 90°05.0'W. Your vessel is on course 068°T, and your speed is 7.8 knots. Local apparent noon (LAN) occurs at 1145 zone time, at which time a meridian altitude of the Sun's lower limb is observed. The observed altitude (Ho) for this sight is 54°51.5'. What is the latitude at 1200 ZT? #6 On 16 December your 1810 zone time DR position is LONG 129°46.5' W. At that time you observe Polaris with a sextant altitude (hs) of 23°56.8'. The chronometer time of the sight is 03h 12m 31s, and the chronometer error is 02m 16s fast. The index error is 2.5' off the arc, and the height of eye is 52.6 feet. What is your latitude by Polaris? #7 On 24 September your 1841 zone time DR position is LAT 25°15.0' N, LONG 129°34.5' E. At that time you observe Polaris with a sextant altitude (hs) of 25°20.8'. The chronometer time of the sight is 09h 38m 12s, and the chronometer error is 03m 12s slow. The index error is 4.3' off the arc, and the height of eye is 52.0 feet. What is your latitude by Polaris? #8 On 15 July at 0447 ZT, your vessel's DR position is LAT 22°42' N, LONG 126°36' E. At approximately this time, you obtain a sextant altitude (hs) of Polaris reading 23°46.2' with an index error of 1.6' off the arc. Your chronometer reads 08h 48m 28s, and is 1m 16s fast. What is your latitude by Polaris, given a height of eye of 33 feet? #9 On 13 October at 1847 ZT, your vessel's DR position is LAT 42°17.4' N, LONG 138°46.2' W. At approximately this time, you obtain a sextant altitude (hs) of Polaris reading 42°16.8', with an index error of 3.2' on the arc. Your chronometer reads 03h 45m 20s and is 1m 32s slow. What is your latitude by Polaris, given a height of eye of 44 feet? #10 On 22 July at 0720 ZT, in DR position LAT 20°38.2'N, LONG 87°16.0'W, you observe the Moon's lower limb. The sextant altitude (hs) is 38°32.6, and the chronometer reads 01h 18m 14s. The chronometer is 01m 28s slow. The index error is 3.1' off the arc, and the height of eye is 68 feet. What is the azimuth (Zn) and intercept (a) of this sight from the assumed position? #11 On 5 May at 1953 zone time, you take a sextant observation of Polaris. Your vessel's DR position is LAT 29°30.0' N, LONG 66°25.7' W, and your sextant reads 29°07.2'. Your chronometer reads 11h 51m 45s, and your chronometer error is 01m 36s slow. Your height of eye is 56 feet, and the index error for your sextant is 1.5' on the arc. What is the latitude of your vessel from your observation of Polaris? #12 On 25 May your vessel's 1917 zone time position is LAT 24°16.0'N, LONG 017°26.0'W. At that time a sextant observation of the planet Saturn was made. The sextant altitude is 63°05.1', and the chronometer reads 08h 18m 24s. The index error is 4.5' off the arc, and the chronometer error is 01m 05s fast. Your height of eye is determined to be 62.0 feet. What is the azimuth (Zn) of this sight using the assumed position? #13 On 18 November your 1750 zone time DR position is LONG 110°16.0' W. At that time you observe Polaris with a sextant altitude (hs) of 21°29.8'. The chronometer time of the sight is 00h 52m 43s, and the chronometer error is 02m 18s fast. The index error is 3.2' on the arc, and the height of eye is 49.5 feet. What is your latitude by Polaris? #14 On 3 January your 1759 zone time DR position is LONG 60°53.2' W. At that time you observe Polaris with a sextant altitude (hs) of 22°55.8'. The chronometer time of the sight is 09h 57m 10s, and the chronometer error is 02m 26s slow. The index error is 2.9' off the arc, and the height of eye is 52.5 feet. What is your latitude by Polaris? #15 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? #16 On 24 March your 0800 zone time fix gives you a position of LAT 22°16.0'N, LONG 31°45.0'W. Your vessel is steaming a course of 285°T at a speed of 16.5 knots. An observation of the Sun's upper limb is made at 0938 zone time, and the observed altitude (Ho) is 46°32.2'. The chronometer reads 11h 41m 01s, and the chronometer error is 02m 50s fast. Local apparent noon occurs at 1214 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) for this sight is 68°55.8'. Determine the vessel's 1200 zone time position. #17 On 11 November your 0730 zone time position was LAT 19°58.0'N, LONG 143°54.0'W. Your vessel was steaming on course 084°T at a speed of 15.0 knots. An observation of the Sun's lower limb was made at 0931 ZT. The chronometer read 07h 29m 22s and was slow 02m 22s. The observed altitude (Ho) was 44°17.6'. LAN occurred at 1125 zone time (ZD +10). The observed altitude (Ho) was 52°17.4'. What was the longitude of your 1200 zone time running fix? #18 On 20 November your 0612 zone time (ZT) position was LAT 25°38.0'N, LONG 166°54.0'W. Your vessel was steaming on course 126°T at a speed of 20.0 knots. An observation of the Sun's lower limb was made at 0854 ZT. The chronometer read 07h 51m 14s and was slow 02m 52s. The observed altitude (Ho) was 27°58.3'. LAN occurred at 1147 ZT. The observed altitude (Ho) was 45°35.0'. What was the longitude of your 1147 ZT running fix? #19 On 22 February your 0800 zone time position is LAT 24°16'S, LONG 95°37'E. Your vessel is on course 126°T at a speed of 14 knots. An observation of the Sun's lower limb is made at 0945 zone time. The chronometer reads 03h 47m 22s, and the chronometer error is 02m 37s fast. The observed altitude (Ho) is 57°02.1'. LAN occurs at 1148 zone time, and a meridian altitude of the Sun's lower limb is made. The observed meridian altitude (Ho) is 75°22.3'. Determine the vessel's 1200 zone time position. #20 On 29 April your 0530 zone time position was LAT 23°04.0'S, LONG 162°12.0'E. Your vessel was steaming on course 120°T at a speed of 9.0 knots. An observation of the Sun's upper limb was made at 0830 ZT. The chronometer read 09h 27m 32s and was slow 02m 24s. The observed altitude (Ho) was 24°58.0'. LAN occurred at 1205 zone time. The observed altitude (Ho) was 52°04.0'. What was the longitude of your 1200 zone time running fix? #21 On 20 September your 0730 zone time position was LAT 28°58.0'N, LONG 152°26.0'W. Your vessel was steaming on course 225°T at a speed of 19.0 knots. An observation of the Sun's lower limb was made at 0931 ZT. The chronometer read 07h 29m 20s and was slow 02m 22s. The observed altitude (Ho) was 44°14.4'. LAN occurred at 1206 zone time. The observed altitude (Ho) was 62°49.5'. What was the longitude of your 1200 zone time running fix? #22 On 15 August your 0512 zone time position was LAT 29°18.0'N, LONG 57°24.0'W. Your vessel was steaming on course 262°T at a speed of 20.0 knots. An observation of the Sun's lower limb was made at 0824 ZT. The chronometer read 00h 22m 24s and was slow 01m 34s. The observed altitude (Ho) was 38°16.7'. LAN occurred at 1204 zone time. The observed altitude (Ho) was 74°58.0'. What was the longitude of your 1204 zone time running fix? #23 On 17 January your 0730 zone time position was LAT 22°26.0'N, LONG 152°17.0'E. Your vessel was steaming on course 136°T at a speed of 17.0 knots. An observation of the Sun's lower limb was made at 1015 ZT. The chronometer read 00h 13m 23s and was slow 01m 49s. The observed altitude (Ho) was 40°25.7'. LAN occurred at 1222 zone time. The observed altitude (Ho) was 47°48.1'. What was the longitude of your 1200 zone time running fix? #24 On 26 July your 1901 ZT position is LAT 28°28'N, LONG 157°16'E when you take an observation of Jupiter. The chronometer at the time of the sight reads 08h 54m 34s and is 06m 24s slow. The sextant altitude (hs) is 33°51.5'. The index error is 2.8' off the arc, and the height of eye is 48 feet. What are the azimuth (Zn) and intercept (a) for this sight using the assumed position? #25 On 28 April your vessel's 0515 zone time position is LAT 23°26'S, LONG 95°30'E. At this time, the observed altitude (Ho) of the star Rigil Kentaurus is 24°51.4'. Your chronometer reads 11h 16m 36s and is 01m 18s fast. What is the intercept (a) based on the assumed position method? #26 On 17 April your vessel's 1856 zone time DR position is LAT 22°35.0'N, LONG 63°15.0'W. At that time, a sextant observation of the star Sirius is made. The sextant altitude is 42°45.0' and the chronometer reads 10h 59m 27s. The index error is 2.6' off the arc, and the chronometer error is 03m 01s fast. Your height of eye is determined to be 45 feet. What is the computed altitude (Hc) and azimuth (Zn) for this sight using the assumed position? #27 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? #28 On 5 April at 0509 zone time, morning stars were observed and the vessel's position was LAT 28°32'N, LONG 177°13.0'W. Your vessel is steaming at 19.0 knots on a course of 258°T. A sextant observation of the Sun's lower limb is made at 1021 zone time. The chronometer reads 10h 20m 09s, and the sextant altitude (hs) is 58°06.6'. The index error is 1.0' off the arc, and the chronometer error is 00m 54s slow. Your height of eye on the bridge is 55.0 feet. What is the azimuth (Zn) of this sight using the assumed position? #29 On 10 January at 0550 ZT, morning stars were observed, and the vessel's position was determined to be LAT 25°16.0'N, LONG 123°18.0'W. Your vessel is steaming at 22.0 knots on a course of 295°T. A sextant observation of the Sun's lower limb is made at 0915 ZT. The chronometer reads 05h 14m 02s, and the sextant altitude is 24°00.7'. The index error is 2.6' off the arc, and the chronometer error is 01m 34s slow. Your height of eye on the bridge is 55.0 feet. What is the azimuth (Zn) of this sight using the assumed position? #30 On 4 July at 0630 ZT, morning stars were observed, and the vessel's position was determined to be LAT 21°15.0'S, LONG 21°20.0'W. Your vessel is steaming at 13.0 knots on a course of 146°T. A sextant observation of the Sun's lower limb is made at 0915 ZT. The chronometer reads 10h 14m 27s, and the sextant altitude is 25°29.8'. The index error is 3.1' off the arc, and the chronometer error is 0m 53s slow. Your height of eye on the bridge is 48.0 feet. What is the azimuth (Zn) of this sight using the assumed position?
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