Coastal navigation lrg
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This document provides guidance on chartwork and fixing conventions. It discusses: 1. Chartwork conventions such as position lines, tidal streams, clearing bearings, and position fixing methods. 2. Guidance on fixing positions including visual fixes using bearings, radar fixes using ranges, and horizontal sextant angle fixes. 3. Details on calculating tidal streams and estimating positions based on dead and estimated reckoning.
Coastal navigation lrg
- 1. CHARTWORK AND FIXING Gruntproductions 2009 A Brief by Lance Grindley
- 2. Gruntproductions 2009 CHARTWORK CONVENTIONS 140 (142) 0800 06 12 1.2 B 060900 06 Force 5 Planned TrackPlanned Track (To be made good):(To be made good): A bold thick line.A bold thick line. CourseCourse: Along the track.: Along the track. Course to SteerCourse to Steer: In brackets.: In brackets. SpeedSpeed: Vertically in a box.: Vertically in a box. DR (Dead Reckoning)DR (Dead Reckoning): Allowing for direction steered: Allowing for direction steered at speed through the water only and for NO OTHER factors.at speed through the water only and for NO OTHER factors. Tidal StreamTidal Stream: Three arrow heads from a tidal diamond,: Three arrow heads from a tidal diamond, show rate and effective time.show rate and effective time. WindWind:: EP (Estimated Position)EP (Estimated Position): Estimated from course steered through water,: Estimated from course steered through water, allowing for wind, tidal stream, current etc.allowing for wind, tidal stream, current etc.
- 3. Gruntproductions 2009 CHARTWORK CONVENTIONS Distance to DestinationDistance to Destination Shown in milesShown in miles.. Expected time in a positionExpected time in a position DarknessDarkness Across the trackAcross the track Raising and Lowering of LightsRaising and Lowering of Lights Change of ChartChange of Chart 1810 SS Wolf Rock Lt 0547SR Chart 2052 230 0800
- 4. Gruntproductions 2009 POSITION LINES Visual bearing from an objectVisual bearing from an object Visual bearing transferredVisual bearing transferred Radar range/VSARadar range/VSA Radio Fixing AidRadio Fixing Aid Astronomical position lineAstronomical position line SUN 0932 0900
- 5. Position line by transit Ship f Gruntproductions 2009
- 6. Gruntproductions 2009 CHARTWORK CONVENTIONS Potential DangersPotential Dangers - near track should- near track should be highlightedbe highlighted Safe DepthSafe Depth - hatch in- hatch in LDL for ship and HOTLDL for ship and HOT Clearing BearingsClearing Bearings - Solid arrow- Solid arrow heads towards object, NMT or NLTheads towards object, NMT or NLT Wheel over bearings (2)Wheel over bearings (2) - show- show position and est time with openposition and est time with open arrow head, show wheel if notarrow head, show wheel if not standardstandard 195(196) 181(182) 105(104) NM T 200 NMT176 NM T 160 140 090
- 7. POSITION LINES LEADING TOPOSITION LINES LEADING TO FIXESFIXES ►Compass or Gyro bearing (3 or more)Compass or Gyro bearing (3 or more) ►Transit (must be sensitive)Transit (must be sensitive) ►Relative bearingRelative bearing ►Horizontal Sextant AngleHorizontal Sextant Angle ►Vertical Sextant AngleVertical Sextant Angle ►Range by optical instrumentsRange by optical instruments ►Range by raising/lowering of lightsRange by raising/lowering of lights (Horizon range)(Horizon range) Gruntproductions 2009
- 8. Gruntproductions 2009 POSITION LINES LEADING TO FIXESPOSITION LINES LEADING TO FIXES ►SoundingsSoundings ►Astronomical position lineAstronomical position line ►Radar rangeRadar range ►D/F bearingD/F bearing ►Radio fixing aidsRadio fixing aids
- 9. Gruntproductions 2009 USING CHARTSUSING CHARTS ►Always use the largest scale chartAlways use the largest scale chart appropriate to the purpose:appropriate to the purpose: Corrected first.Corrected first. More detail.More detail. ►Use nearest compass rose:Use nearest compass rose: Correct Variation.Correct Variation. Less projection distortion.Less projection distortion. Parallel ruler has less distance to travel.Parallel ruler has less distance to travel.
- 10. Gruntproductions 2009 USING CHARTSUSING CHARTS ►Transfer position by range and bearing andTransfer position by range and bearing and Lat and Long.Lat and Long. ►Check unit of depth.Check unit of depth. ►Measure distance opposite latitude -Measure distance opposite latitude - Mercator.Mercator. ►Only one chart on the table at any one time.Only one chart on the table at any one time. ►Use soft pencil - Don’t dig.Use soft pencil - Don’t dig. ►Don’t doodle !!!!Don’t doodle !!!!
- 11. Gruntproductions 2009 CHANGING CHARTSCHANGING CHARTS ►Transferred positions may be fix, DR or EP.Transferred positions may be fix, DR or EP. ►Transfer position by range and bearing andTransfer position by range and bearing and Lat and Long.Lat and Long. ►Note down position in Nav Record Book.Note down position in Nav Record Book. ►Plot onto new chart.Plot onto new chart. ►Fix to verify position as soon as practicable.Fix to verify position as soon as practicable.
- 12. Gruntproductions 2009 The FixThe Fix 0926 Visual FixVisual Fix :: -made up of transits,-made up of transits, gyro bearings orgyro bearings or compass bearingscompass bearings Radar FixRadar Fix:: -made up of at-made up of at least threeleast three radar rangesradar ranges 0957
- 13. Gruntproductions 2009 FIXINGFIXING ►Cross cut of 2 position lines. 3 positionCross cut of 2 position lines. 3 position lines are used as error check.lines are used as error check. ►Use Visual / radar conspicuous points.Use Visual / radar conspicuous points. ►Are points charted ?Are points charted ? ►Avoid blind arcs (visual and radar).Avoid blind arcs (visual and radar). ►Aim for a good angle of cut.Aim for a good angle of cut. ►Aim to fix at least every 6 minutes.Aim to fix at least every 6 minutes.
- 14. Gruntproductions 2009 Horizontal Sextant AnglesHorizontal Sextant Angles ►AdvantagesAdvantages ►Potentially the most accurate method ofPotentially the most accurate method of fixing.fixing. ►Freedom from Gyro repeats.Freedom from Gyro repeats. ►Can be used in event of Gyro failureCan be used in event of Gyro failure.. ►DisadvantagesDisadvantages ►Takes longer to obtain the fix.Takes longer to obtain the fix. ►Manpower intensive.Manpower intensive. ►Requires three suitable fixing pointsRequires three suitable fixing points
- 15. Gruntproductions 2009 Chord of a CircleChord of a Circle
- 16. Gruntproductions 2009 HSA FIXHSA FIX 09000900
- 17. Gruntproductions 2009 HSA FIXHSA FIX ►Plotted using:Plotted using: HSA Lattice chart.HSA Lattice chart. Douglas Protractor.Douglas Protractor. Station Pointer.Station Pointer. ►Beware of circular fixesBeware of circular fixes..
- 18. When not to fix by HSA or bearingsWhen not to fix by HSA or bearings Possible Positions q° q° q° f° f° f° Gruntproductions 2009
- 20. Gruntproductions 2009 FIXING BY RELATIVE ANGLESFIXING BY RELATIVE ANGLES Course030° G15 G45 G80 35 30
- 21. Gruntproductions 2009 VISUAL FIXVISUAL FIX Duration of fixDuration of fix Ship Movement: Delay between first and last bearing been taken. Approx 10-15 Secs = 30 – 100m at 12 Kts
- 22. Gruntproductions 2009 Sources of the Cocked HatSources of the Cocked Hat ►Reading Error:Reading Error: +/- 1/2+/- 1/2 approx 50 Meters at 3nmapprox 50 Meters at 3nm ►Compass Error:Compass Error: Gyro Compass accurate to +/- 1.Gyro Compass accurate to +/- 1. 0.3 = 33 meters at 3nm.0.3 = 33 meters at 3nm.
- 23. Gruntproductions 2009 Detection of Gyro ErrorDetection of Gyro Error ►Transits.Transits. ►Bearing of celestial body.Bearing of celestial body. ►Line of Jetty.Line of Jetty. ►Comparison of observed / chartedComparison of observed / charted bearing from a known position.bearing from a known position. ►Reduction of a cocked hat using StationReduction of a cocked hat using Station Pointer.Pointer.
- 24. Gruntproductions 2009 Running FixRunning Fix 4545 09000900 09000900 0900 Gruntproductions 2009
- 25. Gruntproductions 2009 Range by Vertical AngleRange by Vertical Angle ►Angle measured by sextant.Angle measured by sextant. ►Elevation of charted objects givenElevation of charted objects given above the Datum of MHWS.above the Datum of MHWS. ►Value of MHWS either given orValue of MHWS either given or obtained from Tidal Level Table onobtained from Tidal Level Table on chart.chart. ►Height of tide usually given.Height of tide usually given. ►Beware of index error if given.Beware of index error if given.
- 26. Gruntproductions 2009 Nories TablesNories Tables ►Distance by Vertical Angle (pageDistance by Vertical Angle (page 478)478) ►Calculator can be used if desired.Calculator can be used if desired. ►Tan VSA = h/d where h is height ofTan VSA = h/d where h is height of object and d is distance from object.object and d is distance from object.
- 27. Gruntproductions 2009 Calculating VSA (1)Calculating VSA (1) MHWSMHWS ElevationElevation Gruntproductions 2009
- 28. Gruntproductions 2009 Calculating VSA (2)Calculating VSA (2) MHWSMHWS ElevationElevation Chart DatumChart Datum Sea LevelSea Level Height of TideHeight of Tide Gruntproductions 2009
- 29. Gruntproductions 2009 Calculating VSA (3)Calculating VSA (3) MHWSMHWS ElevationElevation Chart DatumChart Datum Sea LevelSea Level Height of TideHeight of Tide Gruntproductions 2009
- 30. Gruntproductions 2009 Fixing by a bearing and a soundingFixing by a bearing and a sounding M97/1295-9-13
- 31. FixingFixing ProcedureProcedure ► Select objects (consult chart)Select objects (consult chart) ► Write down in notebookWrite down in notebook ► ““Shoot up” objects - think aheadShoot up” objects - think ahead ► Take 3 bearings and shoot up a further markTake 3 bearings and shoot up a further mark ► Time fix to coincide with DR/EPTime fix to coincide with DR/EP ► Take bearings quickly (remember last 2 digits)Take bearings quickly (remember last 2 digits) ► Bow/Quarter first, beam lastBow/Quarter first, beam last ► Note timeNote time ► PlotPlot Gruntproductions 2009
- 32. Selection ofSelection of MarksMarks ►Good cutGood cut ►Near objects to reduce errorsNear objects to reduce errors ►Charted and visible!Charted and visible! ►All visible from same repeaterAll visible from same repeater ►Are they circular?Are they circular? Gruntproductions 2009
- 33. Gruntproductions 2009 SHOOTING UPSHOOTING UP Bn FSA) By bearingsA) By bearings from fixesfrom fixes 1000 1015 1030 190 8
- 34. Gruntproductions 2009 SHOOTING UPSHOOTING UP Bn FS 1000 Hotel Conspic B) By transitsB) By transits A B A. Buoy O Hotel 117A. Buoy O Hotel 117 B. Buoy O Church 088B. Buoy O Church 088 190 8
- 35. Gruntproductions 2009 OPENING BEARINGOPENING BEARING Stab Pt All Saints AllSaintsopens018 W/O First church will openFirst church will open All saints will appearAll saints will appear when Stab Pt bears 018when Stab Pt bears 018
- 36. Gruntproductions 2009 The DR PositionThe DR Position Course Steered and SpeedCourse Steered and Speed through the waterthrough the water FixFix 0900 30
- 37. Gruntproductions 2009 The EP PositionThe EP Position FixFix Course Steered and SpeedCourse Steered and Speed through the waterthrough the water Course and Speed Made GoodCourse and Speed Made Good TidalTidal StreamStream VectorVector FixFix 0900 30 30
- 38. Gruntproductions 2009 FixFix Course RequiredCourse Required TidalTidal StreamStream VectorVector Course to SteerCourse to Steer Radius Vector forRadius Vector for Speed through theSpeed through the waterwater Speed Made GoodSpeed Made Good Course to SteerCourse to Steer
- 39. Gruntproductions 2009 TidalTidal StreamStream VectorVector Course to Steer (3)Course to Steer (3) Course to SteerCourse to Steer Speed Made GoodSpeed Made Good This is a vector (relative velocity)This is a vector (relative velocity) triangle which can be constructedtriangle which can be constructed in any convenient position such asin any convenient position such as the Compass Rosethe Compass Rose
- 40. Gruntproductions 2009 Assessing the TidalAssessing the Tidal StreamStream 14151415 Course Steered and SpeedCourse Steered and Speed through the waterthrough the water 2727 14271427 Course and Speed Made Good Course and Speed Made Good
- 41. Gruntproductions 2009 EP Based on FixesEP Based on Fixes 14151415 Course Steered and SpeedCourse Steered and Speed through the waterthrough the water 2727 14271427 Course and Speed Made Good Course and Speed Made Good 3131
- 42. Gruntproductions 2009 To reach a required positionTo reach a required position 14101410 A AA A 15001500 1515 Direction (Course) and Distance toDirection (Course) and Distance to be steamed in the next 45 minutesbe steamed in the next 45 minutes