Pass Benchmark: 70% (21/30) • Standard: USCG NMC / 46 CFR
USCG Navigation Problems (Set 35)
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Question 1 of 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 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?
Browse Questions in Set 35
30 MCQs #1 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? #2 On 17 March your 1845 DR position is LAT 25°10.0'N, LONG 66°48.0'W. You observe an unidentified star bearing 340°T at an observed altitude (Ho) of 66°25.1'. The chronometer reads 10h 47m 49s, and is 1m 54s fast. What star did you observe? #3 On 22 March your 1834 DR position is LAT 26°13.5'S, LONG 108°36.5'W. You observe an unidentified star bearing 315°T at an observed altitude (Ho) of 66°01.2'. The chronometer reads 01h 32m 37s, and is 01m 50s slow. What star did you observe? #4 At 1300 ZT on 9 May your DR position is LAT 24°00'N, LONG 83°26'W. Determine the computed altitude (Hc) of the Sun for the assumed position nearest to the above given latitude and longitude, given a chronometer time of 07h 00m 00s. #5 On 17 March your 0800 zone time DR position is LAT 21°27.0'N, LONG 65°25.0'W. Your vessel is on course 105°T at a speed of 17.5 knots. What is the zone time of local apparent noon (LAN)? #6 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. #7 On 10 October your 1500 zone time DR position is LAT 27°35.6' S, LONG 44°49.0' W. You are on course 342°T at a speed of 24 knots. Considering their magnitude, azimuth, and altitude, which group includes the three bodies best suited for a fix at star time? #8 On 9 February your 0830 zone time DR position is LAT 22°19.0'N, LONG 64°37.0'E. Your vessel is on course 128°T at a speed of 19.0 knots. What is the zone time of local apparent noon? #9 On 22 July your 1759 DR position is LAT 24°50.2' S, LONG 05°16.0' E. You observe an unidentified star bearing 293°T at an observed altitude (Ho) of 17°52.8'. The chronometer reads 06h 01m 31s, and is 02m 15s fast. What star did you observe? #10 On 27 March your 0330 zone time DR position is LAT 23°32'N, LONG 154°47'E. Your vessel is on a course of 105°T at a speed of 20 knots. What will be the zone time of sunrise at your vessel? #11 Your 0000 zone time position on 13 June is LAT 24°35'N, LONG 142°26'E. Your vessel is on course 245°T, speed is 13.5 knots. What is the zone time of sunrise? #12 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? #13 You observe the lower limb of the Sun at a sextant altitude (hs) of 22°58.6' on 16 June. The index error is 2.0' off the arc. The height of eye is 61 feet. What is the observed altitude (Ho)? #14 On 10 June your 1712 zone time DR position is LAT 25°10.0' S, LONG 06°58.0' E. You are on course 213°T at a speed of 9.0 knots. Considering their magnitude, azimuth, and altitude, which group includes the three stars best suited for a fix at star time? #15 On 3 February your 0550 zone time DR position is LAT 26°16.0' N, LONG 112°05.0' W. Considering their magnitude, azimuth, and altitude, which group includes the three bodies best suited for a fix at star time? #16 On 3 October your 0830 ZT position is LAT 26°15.0'S, LONG 73°16.0'E. Your vessel is on course 280°T at a speed of 19.0 knots. What is the ZT of local apparent noon (LAN)? #17 On 24 July your 1912 zone time DR position is LAT 24°28.0' N, LONG 73°46.5' W. Considering their magnitude, azimuth, and altitude, which group includes the three stars best suited for a fix at star time? #18 On 13 September your 1830 ZT DR position was LAT 23°03'S, LONG 105°16'E when you observe a faint unidentifiable star through a hole in the clouds. The star bore 132.3°T at a sextant altitude (hs) of 29°34.6'. 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? #19 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? #20 On 14 January your 1922 DR position is LAT 27°18.5'S, LONG 67°18.0'E. You observe an unidentified star bearing 054°T at an observed altitude (Ho) of 07°52.1'. The chronometer reads 03h 25m 43s, and is 03m 15s fast. What star did you observe? #21 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)? #22 On 15 October an ex-meridian altitude of the Sun's lower limb at upper transit was observed at 1146 ZT. Your DR position is LAT 22°42.0'N, LONG 139°52.0'E, and your sextant altitude (hs) is 58°30.4'. The index error is 3.4' on the arc, and your height of eye is 56.7 feet. The chronometer time of the observation is 02h 45m 06s, and the chronometer error is 01m 06s slow. Find the latitude at meridian transit from the ex-meridian observation. #23 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? #24 On 16 July your 1920 ZT DR position is LAT 25°36.0' N, LONG 172°18.9' W. Considering their magnitude, azimuth, and altitude, which group includes the three bodies best suited for a fix at star time? #25 On 16 February your 1845 ZT DR position is LAT 25°50.5' N, LONG 46°24.0' W. At that time you observe Polaris with a sextant altitude (hs) of 26°25.5'. The chronometer time of the sight is 09h 47m 30s and the chronometer error is 02m 16s fast. The index error is 2.5' off the arc, and the height of eye is 55.0 feet. What is your latitude by Polaris? #26 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? #27 On 14 January your 0550 ZT DR position is LAT 25°26.0' N, LONG 38°16.0' W. You observe an unidentified star bearing 004.5°T, at an observed altitude (Ho) of 40°10.0'. The chronometer reads 08h 48m 51s and is 01m 22s slow. What star did you observe? #28 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? #29 On 14 January your 1922 ZT DR position is LAT 27°18.5' S, LONG 67°18.0' E. You observe an unidentified star bearing 029°T, at an observed altitude (Ho) of 29°35.0'. The chronometer reads 03h 25m 43s and is 03m 15s fast. What star did you observe? #30 On 10 October your 0930 zone time position is LAT 25°00.0'S, LONG 164°38.6'W. Your vessel is on course 180°T at a speed to 10.0 knots. What is the zone time of local apparent noon (LAN)?
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