Apr 2023 PM TCN
Q.1) While steering 285°C Ballycotton Island light (51° 49.5’ N 007° 59’W) was last sighted in visibility of 5 miles. H.E. = 8m. After one hour, in clear visibility, Roche’s point lt. (51° 47’N 008° 15’W) changed from white to red, current setting 140° T at 3 knots. Leeway due to Northerly wind was 4°. Calculate course and speed made good and both positions.
Answer:
Ballycotton Island:
Geographical range – 2.095√10+2.095√59 = 22.7M
Nominal Range – 22M
Luminous range – 13.4M
CTS – 285°C
Deviation – 10.75°E
Variation – 7°W
True Course – 289°T
Leeway Track – 285°T
CMG – 272°T
SMG – 7.8 Kts
Initial Position: 51°37.1’N; 008°07.4’W
Final Position: 51°37.4’N; 008°19.8’W
Q.2) Own ship in position 51° 30’N 007° 00’W. Another ship is stopped in position 52° 00’N 007° 10’W and drifting. Current in the area is setting SE at 2 knots. Calculate compass course to steer, engine speed and course & speed made good of own ship to meet the other ship after four hours. Also calculate the meeting position.
Answer:
CTS – 348°T
CMG – 359°T
Engine Speed – 7.7 Kts
SMG – 6.1 Kts
Meeting Position: 51°54.4’N; 007°00.9’W
Q.3) While navigating in St. George’s channel TSS, an oil tanker with maximum draft of 18 m observes Tusker rock racon (52° 12’N 006° 12’W) bearing 250° T x 4.4 miles at 2200 hrs. From this position, prepare a detailed plan for a safe passage to reach a position 6 miles due south of Old Head of Kinsale light. Courses have to be plotted with clear markings on the chart and relevant notes for the bridge team.
Plan the Passage as per question