ORD-10

1. ORD-10 Ordinary Piloting Instructors: George Crowl

2. Course Outline • a. Latitude / longitude. Plot positions. • b. Degree system of direction, variation, deviation • c. Measuring speed and distance • d. 24 hour time system • e. UTC / GMT / Zulu time and conversion • f. DR table of headings / distances • g. Use your Sea Scout Pocket Reference!

3. ORD-10a. • Demonstrate your understanding of latitude and longitude. • Using a Mercator chart, demonstrate that you can locate your position from given coordinates and determine the coordinates of at least five aids to navigation.

4. Latitude / Longitude Houston is about 30° north of the equator, and 90° west of Greenwich. Numbers increase up and left in the US.

5. 60 Minutes per Degree • 60 minutes per degree • 1 minute = 1 nautical mile (measured north / south) • 1 NM = 6080 ft • 60 seconds = 1 minute • 1 second = 101 feet • In Java, latitude increases south and longitude increases east. Why?

6. Plotting a Position • Determine the parallels on the chart that bracket the latitude. • Place the pivot point of the compass on the closest line. • Spread the compass until the lead rests on the given latitude. • Move to the approximate longitude and swing an arc.

7. Plotting a Position • The same process is repeated using the longitude scale and the given longitude. • The desired position is the intersection of these two arcs. • If plotted correctly, the intersection should occur at the crest of both arcs.

8. Minutes / SecondsMinutes / Tenths, Hundredths • Measure in degrees, minutes, seconds (N29° 34’ 47”) OR Measure in degrees, minutes, and tenths, hundredths, thousandths (N29° 34.783’) • N 29° 34’ 47” = N 29° 34.783’ • See the left and bottom edges of your chart, and the 1/10’ marks on the middle. • EXERCISE – Plot the following coordinates: • N41°41.4' W072°05.5' • N41°40.2' W072°01.1' • N41-39.6 W071-57.6 • N41-37.5 W071-59.6 • N41-39.0 W072-01.4

9. Plotted Points

10. Determine Coordinates of… • 1. Channel Island Light Fl 8s 20ft 5M • 2. Bowditch Bay Light G9 Fl G 4s • 3. Oyster River Light G1 Fl G 2s • 4. Bowditch Bay Buoy R N 14 • 5. Bowditch Bay Light R16 Fl R 4s

11. Coordinates are: • 1. Channel Is Light N41°41.7' W071°53.7' • 2. BB G9 Fl G 4s N41-37.5 W071-55.0 • 3. OR G1 Fl G 2s N41-36.7 W072-01.0 • 4. BB R14 R N 14 N41-39.8 W072-04.5 • 5. BB R16 Fl R 4s N41-38.8 W072-07.9

12. ORD-10b. • Explain the degree system of compass direction. • Explain variation and deviation, and how they are used to convert between true and compass headings and bearings.

13. Degree System of Compass Direction (Outer Ring) • 360° in a circle, 0° and 360° at North (star) • 090° = East • 180° = South • 270° = West • Any intermediatedirection measuredby numbered angle

14. North Magnetic Pole • Compass does not point N • Changes everywhere • Points 3° E here, so (-) subtract from True

15. Variation (inner circle) • Compass variation – same for all compasses • Plotted on chartcompass rose • Listed on bottomof chart also • Look at your chart

16. Deviation Deflection of a compass needle caused by a magnetic influence

17. Deviation • Different on EVERY boat • Different on EVERY heading for every boat! • Also –E & +W Defiant Compass Swing 4 NOV 06 Motor on, under way TRUE VAR MAG DEV COMP 007 -4 003 -3 000 035 -4 031 -1 030 - - - - 060 092 -4 088 +2 090 120 -4 116 +4 120 154 -4 150 0 150 182 -4 178 +2 180 213 -4 209 +1 210 243 -4 239 +1 240 274 -4 270 0 270 305 -4 301 -1 300 332 -4 328 +2 330 007 -4 003 -3 360

18. Variation, Deviation & Compass Correction • TC VAR MC DEV COMP • 117 -3E 114 +2W 116 • T V Makes Dull Company - • Add Whisky (+W) • Hand compasses = no deviation, because deviation depends on where you are on the boat

19. Sample Deck Log

20. Compass Correction East is Least (-) “-3E” West is Best (+) “+15W”

21. Compass Correction • T True • V Variation • M Magnetic • D Deviation • C Compass • TV Makes Dull Company

22. ORD-10c. • Describe three kinds of devices used aboard ship for measuring speed and/or distance traveled and, if possible, demonstrate their use.

23. Speed Logs • Speed by RPM • Dutchman’s log 5”/30’ = 3.56KT • Ground Log • Chip Log • Patent Log • Taffrail Log • GPS

24. Chip Log

25. Patent / Taffrail Log

27. 10c. Measure Speed and Distance • Distance is measured in • Nautical miles • = 6080 feet • Speed is measured in • Knots • (Nautical miles per hour)

28. Measuring Distance • Always measure distance on the Latitude scale! • OR – use the scale on the chart

29. Why We Use Vertical Scale

30. Measuring Course – Parallel Rules Using parallel rules • B A SSPR p. 22

31. Measuring Course – Plotter • Plotter – align using your dividers • Grommet on longitude line

36. Deck Log Plan Start your deck log with true course and distance. Derive mag course and perhaps compass.

37. Speed Time Distance D (distance) S (speed) = 60 (minutes) T (time)

38. Estimate Speed, Calculate Time 6.0 = 9.3 60x9.3 = 558÷6.0 = 93 = 1+33 60 X

39. ORD-10e. • Explain the 24-hour time system and demonstrate that you can convert between 12- and 24- hour time.

40. 12- vs. 24-Hour Time 12-Hour 24-Hour 12-Hour 24-Hour • 1:00 AM 0100 1:00 PM 1300 • 2:00 AM 0200 2:00 PM 1400 • 3:00 AM 0300 3:00 PM 1500 • 4:00 AM 0400 4:00 PM 1600 • 5:00 AM 0500 5:00 PM 1700 • 6:00 AM 0600 6:00 PM 1800 • 7:00 AM 0700 7:00 PM 1900 • 8:00 AM 0800 8:00 PM 2000 • 9:00 AM 0900 9:00 PM 2100 • 10:00 AM 1000 10:00 PM 2200 • 11:00 AM 1100 11:00 PM 2300 • Noon 1200 Midnight 2400

41. 24-Hour Clock Faces

42. ORD-10d. • Understand Universal Coordinated Time (Greenwich Mean Time or Zulu Time) and zone time. • Demonstrate your ability to convert from one to the other for your local area.

43. Zone Time

44. UCT / GMT / Zulu • Zone Standard DST Zulu • Eastern 1000 1100 1500 • Central 0900 1000 1500 • Mountain 0800 0900 1500 • Pacific 0700 0800 1500

45. ORD-10f. • Make a dead reckoning table of compass and distances (minimum three legs) between two points, plot these on a chart, and determine the final position. • Note: Ideally this requirement should be met while under way. If this is not possible, it may be simulated using charts.

46. Dead Reckoning • Record of ships progress based on • Course • Speed • Time traveled • Known starting point (fix) • Checked every hour, minimum • Checked at every course or speed change

47. Dead Reckoning Terms • DR Dead Reckoning Position • EP Estimated Position • Fix Established position by any means • LOP Line of Position • C Course • S Speed

48. Dead Reckoning (DR) • Start from a fix • Label all lines on chart • Numbers are rounded off • Use Military time • Courses & bearings are 3 digits (045, 218) • Label course with C & bearing with B (C045, B126) • Speed in Knots (1/10 K) placed under the course line • Distance to nearest 1/10 NM place after speed • DR is marked by a dot and semicircle  • Fix is marked by a dot and circle with the time  • Estimated position marked by a dot and square [·] and time

49. Chart Labeling . . . DR FIX 1630 C083 1600 1650 S8.4 D3.6 Estimated Position

50. DR Exercise • Navigator cruising in Bowditch Bay. • Plan the cruise with given data. • We will then give you the instrument readings to make that cruise.