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Woodbridge Cruising Club

Enhance your piloting and navigation skills with the Woodbridge Cruising Club Navigation Refresher. Topics covered include lights, chart plotters, weather, tidal streams, GPS tips, and more.

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Woodbridge Cruising Club

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  1. Woodbridge Cruising Club Navigation Refresher 2019

  2. Pilotage & Navigation • Pilotage: The art of getting lost in sight of land. • Navigation: The distinct and far more complex science used to get lost in offshore waters.

  3. Topics to be Covered • Lights, Shapes • Weather • Chart Plotters, AIS v Radar • Tidal Streams and Tidal Heights. • EPs • GPS tips • DSC VHF Reminder • MOB

  4. QUICK QUIZ

  5. Fog signal At intervals not exceeding 2 minsIf making way If stopped SHAPES - 2 Vessel motor sailingRule 25e

  6. Fog signal At intervals not exceeding 2 mins SHAPES - 4 Power driven vessel restrictedRule 27 in ability to manoeuvre

  7. Fog signal At intervals not exceeding 2 mins SHAPES - 8 Vessel engaged in underwater operations, (restricted in her ability to manoeuvre) Rule 27d Obstruction on the starboard side, clear to port side.

  8. Fog signal At intervals not exceeding 2 mins SHAPES - 10 Vessel not under commandRule 27

  9. LIGHTS -20 Starboard aspect Pilot vesselon duty, under way. RULE 29 Fog signal 1 long blast at intervals not exceeding 2 mins May also sound 4 short blasts

  10. LIGHTS - 15 Starboard aspect Power driven vessel restricted in ability to manoeuvre (probably over 50m)RULE 27 Fog signal 1 long & 2 short blasts at intervals not exceeding 2 mins

  11. LIGHTS - 13 Port aspect Power driven vessel towing. Tug under 50m . Restricted in ability to manoeuvre. Tow >200m. RULE 24 & 27 Fog signal 1 long & 2 short blasts - intervals not exceeding 2 mins followed by 1 long & 3 short blasts from towed vessel, or last in tow

  12. LIGHTS - 21 Starboard aspect Power driven vessel constrained by draught probably over 50m. Under way. RULE 23&28 Fog signal 1 long & 2 short blasts at intervals not exceeding 2 mins

  13. LIGHTS - 23 Port aspect Vessel not under commandMaking way. RULE 27 Fog signal 1 long & 2 short blasts at intervals not exceeding 2 mins

  14. LIGHTS - 18 Aspect unknown Vessel engaged in underwater operations, Not making way. obstruction on the red side, clear to pass on the green side. RULE 27 Fog signal 1 long & 2 short blasts at intervals not exceeding 2 mins

  15. LIGHTS - 29 Aspect unknown Fishing vesselother than trawler. Not making way RULE 26c Fog signal 1long & 2 short blasts at intervals not exceeding 2 mins.

  16. Rules of the road Who gives way wind Two sailing vessels on opposite tacks Yacht B on port tack must give way to the yacht on starboard tack A B B

  17. Rules of the road Who gives way wind Yachts on the same tack Windward yacht A gives way to the leeward yacht A A B

  18. Rules of the road Who gives way wind Two vessels under power Both A and B turn to starboard B B A A

  19. Sound Signals Manoeuvring signals Turning to starboard One short blast Turning to port Two short blasts Operating engines astern Three short blasts

  20. Sound Signals Warning signal Five or more rapid short blasts Unsure of your intentions

  21. Sound Signals Fog signals One long blast Power driven vessel making way in restricted visibility

  22. Sound Signals Fog signals Two long blasts Power driven vessel not making way in restricted visibility

  23. Sound Signals Fog signals One long and two short blasts Vessel sailing in restricted visibility

  24. Sound Signals Fog signals One long and two short blasts Fishing vessel in restricted visibility

  25. WEATHER

  26. Gradient or 'Weather Map' Wind 30º Initial direction Backed wind (Anticlockwise) Veered wind (Clockwise) 15º Friction backs gradient wind by about 30 degrees over land and 15 degrees over sea EFFECT OF SURFACE FRICTION

  27. Wind Aloft Land and Sea Winds Diverge Strong Wind Light Wind Sea and Land Winds Converge COMBINED WIND EFFECTS

  28. BUYS BALLOT'S LAW 992 1000 1024 1008 1016 1032 Low Pressure High Pressure Buys Ballot's Law In the Northern Hemisphere, if you stand with your back to the wind, the LOWPRESSURE area is to your left H L

  29. VISIBILITY CRITERIA Good More than 5 miles Moderate 5 to 2 miles Poor 2 miles to 1000 metres Fog Less than 1000 metres Dense fog Mist or Haze 1000 to 2000 metres

  30. PRESSURE AND TENDENCY Tendency = Change in 3 Hours Steady Less than 1 mb Slowly Less than 3 mb Quickly 3.5 to 6mb Very Rapidly More than 6 mb Rising Higher Falling Lower

  31. USE OF WEATHER FORECASTS • Determine weather for the day • Determine where the best shelter is: • Imminent – within 6 hours from forecast • Soon - 6 to 12 hours from forecast • Later – over 12 hours from forecast • Decide when to sail • Decide whether it is prudent to: • Sail • Stay at anchor • Run for shelter

  32. Plotters ETC

  33. Chart Plotters, Tablets & Smart Phones • “Chart Plotters” have transformed life for the cruising sailor. • Plotter with AIS overlay makes amazing package • AIS is NOT a radar substitute – BUT! • On a budget it’s the one to go for. • Short handed sailing much easier with a plotter. • Record your Track on leaving the Deben - return in poor vis then simple just follow your track. • Navionics on a Smart Phone. £34. • Plotters tend to make us all LAZY about log keeping and plotting on a chart. • Do they make us Over-confident?

  34. Pencil & Charts • Why bother with conventional navigation? • If our electronics fail its all we have! - e.g. Lightning Strike! (EMP) • It is still “Good practice”. • Not quite into paperless sailing yet? • It can be very satisfying. • If we don’t use it we lose it! • Extra interest on a long passage?

  35. TIDAL STREAMS

  36. Tidal Streams • Getting the tide right is ESSENTIAL . • Tidal Atlas NP 249 & NP251 for local use • Reeve -Fowkes an alternative if you prefer. • Tide rates only accurate if used properly – WITH - • Computation of Rates table. • Instant view of direction throughout the day. • Tidal Diamonds never where you want them. • Data box never on the part of chart you need • Small and not easy to read in poor light • Beware different REFERENCE Ports! • NP 251 Dover – NP249 Sheerness

  37. TIDAL STREAM ATLAS Stream Slack 03,05 Rate of stream 0.3 kn at Neaps 0.5 kn at Springs Rate of stream 1.2 kn at Neaps 2.3 kn at Springs 12,23

  38. TIDAL DIAMONDS 3 hours before HW Springs 2.9 kn Neaps 1.5 kn Stream setting towards 318(T)

  39. HW - 2½ hrs 0930 HW - 2 1030 HW - 1½ hrs HW - 1 1130 HW - ½ hr HW 1200 HW 1230 HW + ½ hr HW + 1 1330 HW + 1½ hrs HW + 2 1430 HW + 2½ hrs HOURS RELATED TO HIGH WATER Time of High Water = 1200

  40. TIDES • To make getting the correct tidal hour easier • Half an hour before & half an hour after • Look up the tide then adjust it to: • On the hour • 15 min past • Half past • 45 min past • Never more than 7 min out. • Mark up Atlas with your watch time.

  41. Mean Range PLYMOUTH COMPUTATION OF RATES TIDAL STREAM RATE (in tenths of a knot) 40 30 60 70 50 20 10 6m 5m Springs Springs 4m 3m Neaps Neaps 2m 1m 60 70 10 20 30 40 50 Tenths of a Knot

  42. Mean Range PLYMOUTH COMPUTATION OF RATES TIDAL STREAM RATE (in tenths of a knot) 40 30 60 70 50 20 10 6m 5m Springs Springs Rate of stream at Neaps = 2.3 knots (from tidal stream atlas or diamonds) 4m 3m Neaps Neaps 2m 1m 60 70 10 20 30 40 50 Tenths of a Knot

  43. COMPUTATION OF RATES Mean Range PLYMOUTH TIDAL STREAM RATE (in tenths of a knot) 40 30 60 70 50 20 10 6m 5m Springs Springs 4m Rate of stream at Springs = 4.6 knots (from tidal stream atlas or diamonds) 3m Neaps Neaps 2m 1m 60 70 10 20 30 40 50 Tenths of a Knot

  44. COMPUTATION OF RATES Mean Range PLYMOUTH TIDAL STREAM RATE (in tenths of a knot) 40 30 60 70 50 20 10 6m 5m Springs Springs 4m 3m Neaps Neaps 2m 1m 60 70 10 20 30 40 50 Tenths of a Knot

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