Exercise 1a Positions, Bearings, Distances and Symbols
Chart 5047
Name the conspicuous features in the following positions:
51° 01.3¢N 4° 31.5¢W
51° 13.3¢N 3° 28.5¢W
51° 26.0¢N 3° 46.0¢W
51° 30.4¢N 3° 40.2¢W
51° 27.5¢N 3° 24.1¢W
51° 41.1¢N 3° 50.9¢W
51° 33.9¢N 4° 20.0¢W
51° 28.9¢N 3° 10.4¢W
51° 20.4¢N 3° 06.4¢W
51° 31.5¢N 2° 46.8¢W
Find the latitude and longitude of the following conspicuous features:
Lundy Island South lighthouse
Scarweather lightvessel
Swansea pilot station
Bideford Fairway buoy
St. Gowans lightvessel
Caldey Island lighthouse
Swansea airport aero RC
Flat Holm lighthouse
Minehead light
Horseshoe Rocks buoy
Exercise 1b: Positions, Bearings, Courses, Distances and Transits.
1. A ship observes the chimney on Breaksea Point to be in transit with St. Hilary radio masts (51° 28¢N 3° 24¢W). Find the true bearing of the transit and also the latitude and longitude of the ship, given that the ship is 4.0 miles from Breaksea Point.
2. The water tower (51° 31¢N 3° 40¢W) is seen in transit with the Middle Nash buoy, while at the same time Nash Point light is seen to be changing from white to red. Find the true transit bearing and the ship’s position.
3. A sounding of 20 metres was obtained while Nash Point lighthouse bore 076°T. Give the latitude and longitude of the ship.
Chart 5138
4. Find the course and distance from Kaliti Point bearing 090°T x 5.0¢ to Gannet Island light bearing 090°T x 5.0¢. (170°T x 12.3’)
5. Find the course and distance from 36° 30.0¢S 175° 03.5¢E to Auckland pilot station. (216°T x 19.3’)
6. Position 1: Maria Island light bearing 210°T x 3.2’.
Position 2: Flat Rock light bearing 310°T x 3.5¢.
Find: the latitude and longitude of position 1; (36 39.7S 175 02.2E)
the latitude and longitude of position 2; (36 29.0S 174 58.8E)
the course and distance from position 1 to position 2. (165°T x 11.1’)
7. Position 1: Cow Island bearing 055°T, Dead Mans Point bearing 099°T.
Position 2: Gannet Rock range 7.5’, Northern Point of Black Rocks range 6’.
Find: the latitude and longitude of position 1; (36 50.7S 175 20.0E)
the latitude and longitude of position 2; (36 37.5S 175 14.2E)
the course and distance from position 1 to position 2. (341°T x 13.9’)
Exercise 1c Geographical, Nominal & Luminous Range, Tidal Streams & Depths
Chart 5048
1. Define; a) Nominal Range, b) Luminous Range,
c) Geographical Range.
2. With reference to Hook Head light, what is the a) Nominal Range,
b) Height above MHWS.
3. What is the a) Nominal Range of Youghal red light
b) The limiting bearings of the red light.
4. With reference to Ballycotton Island light, what is the Nominal Range,
Luminous Range if the prevailing visibility is 10 nautical miles.
5. What is the Geographical Range of Ballynacourty Point light for an observer whose height of eye is 12 metres.
6. What is the Luminous Range of Old Head Of Kinsale light if the prevailing visibility is; 20 nautical miles, 2 nautical miles, 7 nautical miles
7. At what distance would Roche Point light be first sighted if the prevailing visibility is 5 miles and the height of eye is 4 metres.
8. At what distance would Coningbeg lightvessel light be first sighted if the prevailing visibility is 5 miles and the height of eye is 4 metres.
9. What is the height of Youghal light above; a) MLWS b) MHWN.
10. What is the height of Tuskar Rock light above MHWN.
11. State the meaning of the symbol in position Latitude 51° 43.0¢N Longitude 8° 16.5¢W
12. If High Water at Cobh is at 1500 hrs what is the neap tidal stream in Youghal Bay at; 1000 hrs & 1700 hrs.
13. If High Water at Cobh is at 1500 hrs what is the spring tidal streams will a ship experience to the East of Tuskar Rock between; a) 1130 to 1230 hrs,
b) 1800 to 2000 hrs.
14. If High Water, spring tides, at Cobh is at 1930 hrs what will be the total distance that a vessel drifts between 1430 and 1730 hrs in the proximity of Coningbeg lightvessel.
15. If High Water, neap tides, at Cobh is at 1600 hrs state the direction and distance that a vessel will drift between 1800 and 2130 hrs in the proximity of tidal diamond E.
Exercise 2a Horizontal Sextant Angles, Vertical Sextant Angles
Chart 5056
1. Start Point lighthouse > 65° < Stoke Fleming church tower > 36° < Nimble Rock.
Find the position of the vessel. (50 14.7N 003 30.0W)
2. Berry Head > 28° < Hope’s Nose > 132° < Straight Point lighthouse.
Find the position of the vessel. (50 29.8N 003 23.4W)
3. Hill top, 142 m, Beer Head, bearing 294°G.
Hill top, 175 m, NE of Lyme Regis, “ 024°G.
Hill top, 187 m, Golden Cap, “ 053°G.
Find a) the position of the vessel; (50 39.3N 002 58.4W)
b) the gyro error. (3oH)
4. Bill of Portland lighthouse bearing 090°T and subtending a vertical angle 0° 32.7¢.
Find the position of the vessel. (50 30.8N 002 31.2W)
5. St Albans Head coastguard station bearing 330°C.
Anvil Point lighthouse bearing 016°C and subtending a V.S.A. 0° 24.2¢.
Find the position of the vessel. (50 32.1N 001 55.8W)
6. Anvil Point castle bearing 232°G.
Needles Channel buoy bearing 105°G.
Hill top, 198 m, NW of Swanage subtending a V.S.A. 0° 52.5¢.
Find a) the position of the vessel; (50 39.8N 001 48.8W)
b) the gyro error. (Nil)
Exercice 2b Horizontal Sextant Angles, Vertical Sextant Angles, Transits
1. Find the courses, and distance on each course, from the position 51° 13.5¢N
4° 11.0¢W to a position with Foreland Point lighthouse abeam at distance 2.0 miles and thence to a position with Hurlstone Point abeam at distance 1.3 miles. (077t x 14.8’ & 096t x 8.2’)
2. Find the courses and distances from the position with Nash Point lighthouse > 60° < Breaksea Point chimney > 53° < Breaksea Lanby, until Sand Ridge buoy is abeam at distance 5 cables, and from that position to a position with Bull Point lighthouse abeam at distance 1.8 miles. (257t x 14.7’ & 263t x 14.2’)
3. A ship observes the chimney (128) on Breaksea Point to be in transit with the 4 chimneys NNE of it.
Find the true bearing of the transit and the vessel’s position by Lat and Long given that she is 2.4 miles from the chimney. (027t; 51 20.8N 003 26.1W)
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dariusz.lipinski