PART B - DEAD RECKONING AND ESTIMATED POSITION. Use RYA Chart 3. Use Variation 6°W throughout


1. At 1000 DST a vessel leaves the Quaker safe water mark, 45°40’.70N 006°13’.80W, steering 330°(M) at 5.0 kts. a) Plot the DR position at 1100 DST. b) How reliable is this position likely to be? Give reasons. c) Select true or false from each of the following statements: i) If the tidal set was 180°(T), the vessel’s actual position would be north of the DR ii) If the tidal set was 270°(T), the vessel’s actual position would be west of the DR


2. a) From the DR position in Question 1 plot the EP if the tidal stream is 185°(T) 1.5 kts. b) What is the speed over the ground (SOG) of the boat? c) Is this more or less than the speed through the water? Why? d) If the EP was for 1030 DST what tidal stream should be plotted instead?


3. On Saturday, 5th October at 1443 DST a boat plots a GNSS fix at 45°42’.80N 006°10’.40W and takes a heading of 315°(M) between Robens Island and Dymond Reef. a) What time is HW Victoria? Is it springs or neaps? b) What is the tidal stream between 1443 DST and 1543 DST using tidal Diamond M? c) Plot the EP at 1543 DST if the boat speed is 12 kts. d) What is the course over the ground (COG) of the boat?


4. a) If the boat speed of the boat in Question 3 was only 6 kts would this heading be safe? Draw a projected EP to find out.


b) If a moderate northerly wind blew up and was creating approximately 5° of leeway would you expect the vessel to be to the north or south of the expected COG?


13


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24