To get a better feel for advancing and retarding lines of position for a running fix, the following problems cover this aspect of celestial navigation, AM Sun and LAN (2 LOP). These Coast Guard questions require attention to detail and being accurate.
1. On 30 August 1981 your 0554 zone time (ZT) position was Lat. 25° 39.0' S, Long. 31° 51.0' E. Your vessel was steaming on course 325° T at a speed of 15.0 knots. An observation of the Sun's lower limb was made at 0836 ZT. The chronometer read 06h 38m 36s and was fast 02m 24s. The observed altitude (Ho) was 30° 49.2'. LAN occurred at 1157 ZT. The observed altitude (Ho) was 56° 40.0'. What was the longitude of your 1157 ZT running fix?
A. 30° 59.8' E
B. 30° 57.6' E
C. 30° 55.9' E
D. 30° 52.5' E
2. On 8 February 1981, your 0800 zone time position is Lat. 21 ° 55.0' S, Long. 52° 27.0' W. Your vessel is on course 056° T at a speed of 17.5 knots. An observation of the Sun's lower limb is made at 0938 zone time, and the observed altitude (Ho) is 46° 06.5'. The chronometer reads 12h 37m 23s, and the chronometer error is 1m 24s slow. LAN occurs at 1243 zone time, and a meridian altitude of the Sun's lower limb is made. The observed altitude (Ho) for this sight is 83° 56.1'. Determine the vessel's 1200 zone time position.
A. Lat. 20° 57.0' S, Long. 51° 21.5' W
B. Lat. 20° 58.0' S, Long. 51° 25.5' W
C. Lat. 21° 04.0' S, Long. 51° 12.0' W
D. Lat. 21° 04.0' S, Long. 51° 21.5' W
3. On 4 May 1981, your 0500 zone time position was Lat. 24° 45.0' N, Long. 120° 18.0' W. Your vessel was steaming on course 315° T at a speed of 15.5 knots. An observation of the Sun's upper limb was made at 0830 ZT. The chronometer read 04h 31m 32s and was fast 01m 24s. The observed altitude (Ho) was 40° 11.8'. LAN occurred at 1204 zone time. The observed altitude (Ho) was 80° 05.0'. What was the longitude of your 1300 zone time running fix?
A. Long. 121° 59.2' W
B. Long. 121° 57.4' W
C. Long. 121° 53.5' W
D. Long. 121° 49.8' W
4. On 22 February 1981, your 0800 zone time position is Lat. 24° 16.0' S, Long. 95° 37.0' 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.
A. Lat. 24° 49.3' S, Long. 96° 24.0' E
B. Lat. 24° 49.3' S, Long. 96° 27.2' E
C. Lat. 24° 52.2' S, Long. 96° 24.0' E
D. Lat. 24° 52.2' S, Long. 96° 27.2' E
5. On 29 June 1981, 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.
A. Lat. 26° 02.0' S, Long. 62° 05.0' E
B. Lat. 26° 02.0' S, Long. 62° 23.2' E
C. Lat. 26° 05.1' S, Long. 62° 06.3' E
D. Lat. 25° 56.0' S, Long. 62° 03.0' E
6. On15 August 1981, 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 Z1. The chronometer read 00h 22m 24s and was slow 01 m 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 fix?
A. Long. 59° 52.0' W
B. Long. 59° 54.0' W
C. Long. 59° 58.5' W
D. Long. 60° 02.0' W
