《航海学》课程参考文献（地文资料）CHAPTER 08 PILOTING

CHAPTER 8PILOTINGDEFINITIONANDPURPOSE800.Introductioncuss apilotingmethodologydesigned toensuretheprocedureiscarried out safely and efficiently. These procedures will varyPiloting involves navigating a vessel through restricted wa-fromvessel tovesselaccordingtotheskillandcompositionofters.As in allotherphasesofnavigation,properpreparationandthe piloting team. It is the responsibility of the navigator tostrictattention to detail are very important. This chapter will dis-choose theprocedures applicableto his own situation.PREPARATION801.ChartPreparationMark the Minimum Depth Contour: Determine theminimum depthof waterin whichthe vessel can safelyAssembleRequired Publications:Thesepublicationsoperate andoutline that depth contour on the chart.Dothis stepbeforedoing any other harborpilotingplan-should include CoastPilots,SailingDirections,Lightning. Make this outline in a bright color so that itLists, Lists of Lights, Tide Tables, Tidal CurrentTa-clearly stands out. Carefully examine the area insidebles, Notice to Mariners, and Local Notice tothe contour and mark the isolated shoals less than theMariners.Often,for military vessels,a port will beun-minimum depth whichfall insidethemarked contourder the operational direction of a particular squadron,Determine the minimum depth in which thevessel canobtain that squadron's port OperationOrder.Civilianoperate as follows:vessels should obtain the port's harbor regulationsThesepublications will cover local regulations suchasMinimum Depth = Ship's Draft - Height of Tide +speed limits and bridge-to-bridge radio frequencymonitoring requirements.Assemble the broadcast No-Safety Margin + Squat. (See section 802 and section 819.)tice to Mariners file.Rememberthatoftenthefathometer'stransducerisSelect and Correct Charts:Choose the largest scalenot locatedat the section ofthe hull thatextendsthefurthestbelowthewaterline.Therefore,theindicateddepthofwaterchart available for the approach.Often, the harbor ap-proach will be too long to be represented on only onebelowthefathometertransducer,notthedepthofwaterbe-chart. For example, three charts are required to coverlowthevessel'sdeepestdraft.thewatersfrom the Naval Station in Norfolkto theen-tranceof theChesapeakeBay.Therefore,obtain all theHighlight Selected Visual Navigation Aids (NA-charts required to cover the entire passage.Verify us-VAIDS): Circle, highlight, and label all NAVAIDS oning the Notice to Mariners that the charts in use havethechart.Consult the applicable CoastPilotor SailingDirections to determine a port's best NAVAIDS if thebeencorrectedthroughthelatestchange.Makeanyre-quired changes prior to using the chart.Check thepiloting team has not visited the port previously.TheseLocal Notice to Mariners and the Broadcast Notice toaids can be lighthouses,piers, shorefeatures, or tanks;Mariners file to ensure the chart is fully corrected andanyprominentfeaturethat is displayed onthechart canbe used as a NAVAID.Label critical buoys, such asup to date.Annotate on the chart or a chart correctioncard all the corrections that have been made; this willthose marking a harbor entrance or a traffic separationscheme.Verify charted lights against the Light List ormake iteasierto verify the chart's correction status pri-orto its nextuse.Naval ships will normally preparethe List of Lights to confirm thecharted information isthree sets of charts. One set is for the primary plot, thecorrect.Thisbecomesmostcriticalwhenattemptingtosecond set is for the secondary plot, and the third set isidentify a light at night.Label NAVAIDS succinctlyfortheconningofficerandcaptain.and clearly.Ensureeveryonein the navigation team re-119

119 CHAPTER 8 PILOTING DEFINITION AND PURPOSE 800. Introduction Piloting involves navigating a vessel through restricted wa￾ters. As in all other phases of navigation, proper preparation and strict attention to detail are very important. This chapter will dis￾cuss a piloting methodology designed to ensure the procedure is carried out safely and efficiently. These procedures will vary from vessel to vessel according to the skill and composition of the piloting team. It is the responsibility of the navigator to choose the procedures applicable to his own situation. PREPARATION 801. Chart Preparation • Assemble Required Publications: These publications should include Coast Pilots, Sailing Directions, Light Lists, Lists of Lights, Tide Tables, Tidal Current Ta￾bles, Notice to Mariners, and Local Notice to Mariners. Often, for military vessels, a port will be un￾der the operational direction of a particular squadron; obtain that squadron’s port Operation Order. Civilian vessels should obtain the port’s harbor regulations. These publications will cover local regulations such as speed limits and bridge-to-bridge radio frequency monitoring requirements. Assemble the broadcast No￾tice to Mariners file. • Select and Correct Charts: Choose the largest scale chart available for the approach. Often, the harbor ap￾proach will be too long to be represented on only one chart. For example, three charts are required to cover the waters from the Naval Station in Norfolk to the en￾trance of the Chesapeake Bay. Therefore, obtain all the charts required to cover the entire passage. Verify us￾ing the Notice to Mariners that the charts in use have been corrected through the latest change. Make any re￾quired changes prior to using the chart. Check the Local Notice to Mariners and the Broadcast Notice to Mariners file to ensure the chart is fully corrected and up to date. Annotate on the chart or a chart correction card all the corrections that have been made; this will make it easier to verify the chart’s correction status pri￾or to its next use. Naval ships will normally prepare three sets of charts. One set is for the primary plot, the second set is for the secondary plot, and the third set is for the conning officer and captain. • Mark the Minimum Depth Contour: Determine the minimum depth of water in which the vessel can safely operate and outline that depth contour on the chart. Do this step before doing any other harbor piloting plan￾ning. Make this outline in a bright color so that it clearly stands out. Carefully examine the area inside the contour and mark the isolated shoals less than the minimum depth which fall inside the marked contour. Determine the minimum depth in which the vessel can operate as follows: Minimum Depth = Ship’s Draft – Height of Tide + Safety Margin + Squat. (See section 802 and section 819.) Remember that often the fathometer’s transducer is not located at the section of the hull that extends the furthest below the waterline. Therefore, the indicated depth of water below the fathometer transducer, not the depth of water be￾low the vessel’s deepest draft. • Highlight Selected Visual Navigation Aids (NA￾VAIDS): Circle, highlight, and label all NAVAIDS on the chart. Consult the applicable Coast Pilot or Sailing Directions to determine a port’s best NAVAIDS if the piloting team has not visited the port previously. These aids can be lighthouses, piers, shore features, or tanks; any prominent feature that is displayed on the chart can be used as a NAVAID. Label critical buoys, such as those marking a harbor entrance or a traffic separation scheme. Verify charted lights against the Light List or the List of Lights to confirm the charted information is correct. This becomes most critical when attempting to identify a light at night. Label NAVAIDS succinctly and clearly. Ensure everyone in the navigation team re-

120PILOTINGfers to a NAVAID using the same terminology.Thiswill reduce confusion between the bearing taker, theFinal CourseTransferbearing recorder,and plotter.Highlight Selected Radar NAVAIDS:Highlight ra-End of Turndar NAVAIDS witha triangle instead of a circle.If theNAVAID is suitablefor either visual or radar piloting,it can be highlighted with either a circle or a triangle.BOUEAPVPlot the Departure/Approach Track: This process iscritical for ensuring safepilotage.Consult the FleetGuideandSailingDirectionsforrecommendationsonthebest tracktouse.Look forany information orreg--StartofTurnulations published by the local harbor authorityLacking any of this information, locate a channel orSsionsaferoutedelineated onthe chartand plotthevessel'strack through the channel.Most U.S. ports have welleureodefined channels marked with buoys.Carefully checkthe intended tracktoensureasufficient depth ofwaterunder the keel will exist for the entire passage. If thescale ofthe chartpermits, laythe track outtothe star-Figure 801a.Advance and transfer.board sideofthechannel to allowforanyvessel trafficproceeding in the oppositedirection.Many channelsin thedirection ofthe original coursefrom when the rud-are marked by natural or man-made ranges.A rangeder is put overuntil the new course is reached is calledconsists of two NAVAIDS in line with the center of aadvance.Thedistancethevesselmovesperpendiculartonavigable channel.The navigator can determine histhe original course during the turn is called transfer.Useposition relative to the track by evaluating the align-the advanceand transfercharacteristics of the vessel toment of theNAVAIDS forming the range.Thesedetermine when the vessel must put its rudder over toranges shouldbemeasured tothenearest 0.1°,andthisgain the next course.From that point, fair in a curve be-valueshouldbe marked on thechart.Notonlyarerangtween the original course and thenew course.Mark thees useful inkeeping a vessel on track,they arepointon the original coursewhere the vesselmustput itsinvaluablefor determining gyro error.See section 808.rudder over as the turning point. See Figure 801bLabel the Departure/Approach Track: Label the trackPlot Turn Bearings: A turn bearing is a predeter-courseto the nearest 0.5°.Similarly,label the distance ofmined bearingtoacharted objectfromthetrackpointeach track leg.Place these labels well off thetrack soat which the rudder must be put over in order to makethey do not interfere with subsequent plotting. Highlighta desired turn. Follow two rules when selecting NA-thetrack coursesforeasyreference whilepiloting.ThereVAIDS to be used as turn bearing sources:(I)Theis nothing more frustrating than approaching a turn andNAVAID should be as closeto thebeam as possibleatnotbeingabletodeterminethenextcoursefromthechartthe turn point; and (2) The aid should be on the insidequickly.Often a navigator might plan two separateelbow ofthe turn.This ensures the largest rateof bear-tracks. One track would be for use during good visibilitying change at the turning point, thus marking theand the other for poor visibility.Considerations might inturningpoint more accuratelyPlot the turn bearing toclude concern for thenumberof turns (fewerturnsforthe selected NAVAID from the point on the track atpoor visibility) or proximity to shoal water (smaller mar-which the vessel must put its rudder over to gain thegin for error might be acceptable in good visibility).Innew course. Label the bearing to the nearest o.1othis case, label bothtracks as above and appropriatelymark when touseeach track.If two separatetracks areExample: Figure 80lb illustrates using advance andprovided, the navigator must decide which one to use be-fore the ship enters restricted waters. Never changetransfertodetermineaturnbearing.Ashipproceed-ing on course100isto turn 60to the leftocomeontracks in the middle ofthe transit.a range whichwill guide it up a channel. Fora 600tun and theamount of rudder used,the advance isUse Advance and Transfer to Determine Turning920yardsand thetransferis350yards.Points: The track determined above does not take intoRequired: The bearing of flagpole"FP."when theaccount advance and transferfordetermining turningpoints.SeeFigure 80la.Thedistance thevessel movesrudderis put over

120 PILOTING fers to a NAVAID using the same terminology. This will reduce confusion between the bearing taker, the bearing recorder, and plotter. • Highlight Selected Radar NAVAIDS: Highlight ra￾dar NAVAIDS with a triangle instead of a circle. If the NAVAID is suitable for either visual or radar piloting, it can be highlighted with either a circle or a triangle. • Plot the Departure/Approach Track: This process is critical for ensuring safe pilotage. Consult the Fleet Guide and Sailing Directions for recommendations on the best track to use. Look for any information or reg￾ulations published by the local harbor authority. Lacking any of this information, locate a channel or safe route delineated on the chart and plot the vessel’s track through the channel. Most U.S. ports have well￾defined channels marked with buoys. Carefully check the intended track to ensure a sufficient depth of water under the keel will exist for the entire passage. If the scale of the chart permits, lay the track out to the star￾board side of the channel to allow for any vessel traffic proceeding in the opposite direction. Many channels are marked by natural or man-made ranges. A range consists of two NAVAIDS in line with the center of a navigable channel. The navigator can determine his position relative to the track by evaluating the align￾ment of the NAVAIDS forming the range. These ranges should be measured to the nearest 0.1°, and this value should be marked on the chart. Not only are rang￾es useful in keeping a vessel on track, they are invaluable for determining gyro error. See section 808. • Label the Departure/Approach Track: Label the track course to the nearest 0.5°. Similarly, label the distance of each track leg. Place these labels well off the track so they do not interfere with subsequent plotting. Highlight the track courses for easy reference while piloting. There is nothing more frustrating than approaching a turn and not being able to determine the next course from the chart quickly. Often a navigator might plan two separate tracks. One track would be for use during good visibility and the other for poor visibility. Considerations might in￾clude concern for the number of turns (fewer turns for poor visibility) or proximity to shoal water (smaller mar￾gin for error might be acceptable in good visibility). In this case, label both tracks as above and appropriately mark when to use each track. If two separate tracks are provided, the navigator must decide which one to use be￾fore the ship enters restricted waters. Never change tracks in the middle of the transit. • Use Advance and Transfer to Determine Turning Points: The track determined above does not take into account advance and transfer for determining turning points. See Figure 801a. The distance the vessel moves in the direction of the original course from when the rud￾der is put over until the new course is reached is called advance. The distance the vessel moves perpendicular to the original course during the turn is called transfer. Use the advance and transfer characteristics of the vessel to determine when the vessel must put its rudder over to gain the next course. From that point, fair in a curve be￾tween the original course and the new course. Mark the point on the original course where the vessel must put its rudder over as the turning point. See Figure 801b. • Plot Turn Bearings: A turn bearing is a predeter￾mined bearing to a charted object from the track point at which the rudder must be put over in order to make a desired turn. Follow two rules when selecting NA￾VAIDS to be used as turn bearing sources: (1) The NAVAID should be as close to the beam as possible at the turn point; and (2) The aid should be on the inside elbow of the turn. This ensures the largest rate of bear￾ing change at the turning point, thus marking the turning point more accurately. Plot the turn bearing to the selected NAVAID from the point on the track at which the vessel must put its rudder over to gain the new course. Label the bearing to the nearest 0.1°. Example: Figure 801b illustrates using advance and transfer to determine a turn bearing. A ship proceed￾ing on course 100° is to turn 60° to the left to come on a range which will guide it up a channel. For a 60° turn and the amount of rudder used, the advance is 920 yards and the transfer is 350 yards. Required: The bearing of flagpole “FP.” when the rudder is put over. Figure 801a. Advance and transfer

121PILOTINGFPE39CBC100SPKOSEwwS920 ydsD:BFigure801b.AllowingforadvanceandtransferSolution:used to lay down the track.The chart gets clutteredaround a turn, and thenavigator mustbe ableto see the1.Extendtheoriginal course line,ABslide bar clearly.2.Ataperpendiculardistanceof350yards,thetrans-fer,draw a lineABparallel to the original coureLabel Distance to Go From Each Turn Point: AtlineAB.Thepointof intersection,C,of AB'witheachturningpoint, label the distancetogo until eitherthe new course line is the place atwhich the turn isthe ship moors (inbound) or the ship clears the harborto be completed.(outbound).Foran inboundtransit,a vessel's captain is3.From Cdraw aperpendicular,CD,to the originalmore concerned about time of arrival, so assume acourse line, intersecting at D.speed of advance and label each turn point with timeto4.From D measure the advance,920 yards,backgo until mooringalong the original course line.This locates E,thepoint at which the turn should be started.Plot Danger Bearings: Danger bearings warn a navi-5.The direction of"FP."fromE,058,is the bearinggator he may beapproaching a navigation hazard toowhen theturn should be started.closely. See Figure 801d.Vector AB indicates a ves-Answer:Bearing058osel's intended track. This track passes close to theindicated shoal.Drawa line from theNAVAIDHtan-Plot a Slide Bar for Every Turn Bearing: To assist thegent to the shoal. The bearing of that tangent linenavigator in quicklyrevisinga turn bearing ifthe ship findsmeasured from the ship's track is 074.0°T.In otheritself off track immediately prior to a turn, use a plottingwords, as long as NAVAID H bears less than 074°T astechniqueknown as the slide bar.See Figure 80lc.Drawthe vessel proceeds down its track, the vessel will notthe slide bar parallel to the new course through the turmingground on the shoal. Hatch the side of the bearing linepoint on the original course. The navigator can quickly deon the side of the hazard and label the danger bearingterminea newturnbearingbydead reckoningahead fromNMT (nomore than)074.0°T.For an added margin ofthe vessel's last fix position to where the DR intersects thesafety,the linedoes not haveto be drawn exactlytan-slide bar. The revised turn bearing is simply the bearinggent to the shoal. Perhaps, in this case, the navigatorfrom that intersection point to the turn bearing NAVAIDmight want to set an error margin and draw the dangerbearing at 065°T from NAVAIDH.Lay down a dangerDrawtheslidebarwithadifferent colorfromthat

PILOTING 121 Solution: 1. Extend the original course line, AB. 2. At a perpendicular distance of 350 yards, the trans￾fer, draw a line A’B’ parallel to the original course line AB. The point of intersection, C, of A’B’ with the new course line is the place at which the turn is to be completed. 3. From C draw a perpendicular, CD, to the original course line, intersecting at D. 4. From D measure the advance, 920 yards, back along the original course line. This locates E, the point at which the turn should be started. 5. The direction of “FP.” from E, 058°, is the bearing when the turn should be started. Answer: Bearing 058°. • Plot a Slide Bar for Every Turn Bearing: To assist the navigator in quickly revising a turn bearing if the ship finds itself off track immediately prior to a turn, use a plotting technique known as the slide bar. See Figure 801c. Draw the slide bar parallel to the new course through the turning point on the original course. The navigator can quickly de￾termine a new turn bearing by dead reckoning ahead from the vessel’s last fix position to where the DR intersects the slide bar. The revised turn bearing is simply the bearing from that intersection point to the turn bearing NAVAID. Draw the slide bar with a different color from that used to lay down the track. The chart gets cluttered around a turn, and the navigator must be able to see the slide bar clearly. • Label Distance to Go From Each Turn Point: At each turning point, label the distance to go until either the ship moors (inbound) or the ship clears the harbor (outbound). For an inbound transit, a vessel’s captain is more concerned about time of arrival, so assume a speed of advance and label each turn point with time to go until mooring. • Plot Danger Bearings: Danger bearings warn a navi￾gator he may be approaching a navigation hazard too closely. See Figure 801d. Vector AB indicates a ves￾sel’s intended track. This track passes close to the indicated shoal. Draw a line from the NAVAID H tan￾gent to the shoal. The bearing of that tangent line measured from the ship’s track is 074.0°T. In other words, as long as NAVAID H bears less than 074°T as the vessel proceeds down its track, the vessel will not ground on the shoal. Hatch the side of the bearing line on the side of the hazard and label the danger bearing NMT (no more than) 074.0°T. For an added margin of safety, the line does not have to be drawn exactly tan￾gent to the shoal. Perhaps, in this case, the navigator might want to set an error margin and draw the danger bearing at 065°T from NAVAID H. Lay down a danger Figure 801b. Allowing for advance and transfer

122PILOTINGCUPOCUPOACTUAL_TRANDEDTRAFigure 801c. The slide bar technique.bearing from any appropriate NAVAID in the vicinitytheshallowestwaterexpectedonthetransitandtheves-of any hazard tonavigation.Ensure the track does notsel's maximum draft.Set 90%of this difference as thewarning soundingand 80%ofthis differenceasthedan-crossanydangerbearing.ger sounding. This is not an inflexible rule. There may bePlotDangerRanges:The danger range is analogouspeculiarities about the local conditions that will cause theto the danger bearing.It is a standoff range from an ob-navigator to choose another method of determining hisject to prevent the vessel from approaching a hazardwarning and danger soundings. Use the above method iftoo closely.noothermeansismoresuitable.Forexample:Avesseldraws a maximum of20 feet,and it is entering a channelLabel Warning andDangerSoundings:Todeterminedredged to a minimum depth of 50 feet. Set the warningthe danger sounding, examine the vessel's proposedand danger soundingsat0.9(50ft.-20ft)=27ft and 0.8track and note the minimum expected sounding.The(50ft.-20ft.)=24ft.,respectively.Re-evaluate theseminimum expected sounding isthedifferencebetweensoundings at different intervals along the track when theNMT074INTENDED TRACK-BYFigure801d.Adangerbearing,hatched on thedangerous sideand labeled wih theappropriatebearing

122 PILOTING bearing from any appropriate NAVAID in the vicinity of any hazard to navigation. Ensure the track does not cross any danger bearing. • Plot Danger Ranges: The danger range is analogous to the danger bearing. It is a standoff range from an ob￾ject to prevent the vessel from approaching a hazard too closely. • Label Warning and Danger Soundings: To determine the danger sounding, examine the vessel’s proposed track and note the minimum expected sounding. The minimum expected sounding is the difference between the shallowest water expected on the transit and the ves￾sel’s maximum draft. Set 90% of this difference as the warning sounding and 80% of this difference as the dan￾ger sounding. This is not an inflexible rule. There may be peculiarities about the local conditions that will cause the navigator to choose another method of determining his warning and danger soundings. Use the above method if no other means is more suitable. For example: A vessel draws a maximum of 20 feet, and it is entering a channel dredged to a minimum depth of 50 feet. Set the warning and danger soundings at 0.9 (50ft. - 20ft) = 27ft and 0.8 (50ft. - 20ft.) = 24ft., respectively. Re-evaluate these soundings at different intervals along the track when the Figure 801c. The slide bar technique. Figure 801d. A danger bearing, hatched on the dangerous side and labeled wih the appropriate bearing

PILOTING123minimum expected sounding may change. Carefully803.Weatherlabel the points alongthetrackbetweenwhichthesewarning and danger soundings apply.The navigator should obtain a weather report coveringtheroutewhichheintendstotransit.Thiswillallowhimtoprepare for any heavy weather by stationing extra lookouts,Label Demarcation Line:Clearly label the point onadjusting his speed forpoorvisibility,and preparingforra-the ship's track at which the Inland and InternationalRules of the Road apply.This is applicable only whendar navigation.If the weather is thick, he may want toconsider standing off the harbor until it clears.pilotinginU.S.ports.The navigator can receive weather information anynumber of ways. Military vessels receive weather reportsMark Speed Limits Where Applicable: Often a har-from theirparent squadrons priortocoming intoport.Ma-borwill have a local speed limit in thevicinityofpiersrine band radio carries continuous weather reports. Someothervessels.orshorefacilities.Markthesespeedlim-vessels are equipped with weather facsimile machines.its andthepointsbetween whichtheyareapplicableonSome navigators carry cellular phones to reach shoresidethe chart.personnel and harbor control; these can be used to getweatherreports.Howeverheobtainstheinformation.theMark thePoint of Pilot Embarkation: Someportsnavigator should haveagood idea of theweatherwhereherequire vessels over a certain size to embark a pilot. Ifwill bepiloting.this is the case, mark the point on the chart where thepilot is to embark.804.ThePilotingBriefMark the Tugboat Rendezvous Point:If the vesselAssembletheentirenavigationteamforapilotingbriefrequires atug to moor,mark thetugrendezvous pointprior to entering or leaving port.The vessel's captain andon the chart.navigator should conduct the briefing.All navigation andbridge personnel should attend.Thepilot, if he is already onMark the Chart Shift Point: If more than one chartboard, should also attend.If the pilot is not onboard whenwill be required to completethe passage,markthethe ship's company is briefed, the navigator should imme-track point where the navigator should shift to the nextdiatelybrief himwhenheembarks.Thepilotmustknowchart.the ship's maneuvering characteristics before entering re-stricted waters.The briefing should cover, as a minimum,Harbor Communications:Mark the point on thethe following:chart where the vessel must contact harbor controlAlsomarkthepointwhereavesselmust contactitsDetailed Coverage of theTrack Plan:Goovertheparentsquadrontomake anarrival report(militaryves-planned route in detail. Use the prepared and ap-sels only).proved chart as part of this brief.Concentrateespecially on all theNAVAIDS and soundings whichTides and Currents: Mark the points on the chart forare being used to indicate danger.Cover the buoyagewhich the tides and currents were calculatedsystem in use and the port's major NAVAIDS. PointouttheradarNAVAIDSfor theradaroperator.Often802.TidesAndCurrentsaFleet Guide or SailingDirectionswill havepicturesof a port's NAVAIDS. This is especially importantDetermining thetidaland current conditions oftheportfor thepilotingpartythat has nevertransited this par-which you are entering is crucial.Determining tides andticular port before.If no pictures are availablecurrents is covered in Chapter 9. Plot a graph of the tidalconsider stationing a photographer to take some forrange at the appropriate port for a 24-hour period for thedaysubmissiontoDMAHTCof your scheduled arrival ordeparture.Plottingthe curveforthe24-hourperiodwill coverthose contingenciesthatHarbor Communications:Discuss the bridge-todelay your arrival or departure. Depending on a vessel'sbridge radio frequencies used to raise harbor controldraft and theharbor's depth, somevessels maybe abletoDiscusswhatchannelthevesselissupposedtomonitortransit only at high tide.If this is this case, it is critically im-onitspassageintoportandtheportscommunicationportanttodeterminethetimeand rangeofthetide correctlyprotocol.The magnitude and direction of the current will givethe navigator some idea of the set and drift the vessel willDuties and Responsibilities: Each member ofthe pi-experience during thetransit.This will allowhimto plan inlotingteammusthaveathoroughunderstandingofadvanceforanypotential currenteffectsinthevicinityofhis duties and responsibilities.He must also under-navigation hazards.stand how his part fits into the scheme of the whole

PILOTING 123 minimum expected sounding may change. Carefully label the points along the track between which these warning and danger soundings apply. • Label Demarcation Line: Clearly label the point on the ship’s track at which the Inland and International Rules of the Road apply. This is applicable only when piloting in U.S. ports. • Mark Speed Limits Where Applicable: Often a har￾bor will have a local speed limit in the vicinity of piers, other vessels, or shore facilities. Mark these speed lim￾its and the points between which they are applicable on the chart. • Mark the Point of Pilot Embarkation: Some ports require vessels over a certain size to embark a pilot. If this is the case, mark the point on the chart where the pilot is to embark. • Mark the Tugboat Rendezvous Point: If the vessel requires a tug to moor, mark the tug rendezvous point on the chart. • Mark the Chart Shift Point: If more than one chart will be required to complete the passage, mark the track point where the navigator should shift to the next chart. • Harbor Communications: Mark the point on the chart where the vessel must contact harbor control. Also mark the point where a vessel must contact its parent squadron to make an arrival report (military ves￾sels only). • Tides and Currents: Mark the points on the chart for which the tides and currents were calculated. 802. Tides And Currents Determining the tidal and current conditions of the port which you are entering is crucial. Determining tides and currents is covered in Chapter 9. Plot a graph of the tidal range at the appropriate port for a 24-hour period for the day of your scheduled arrival or departure. Plotting the curve for the 24-hour period will cover those contingencies that delay your arrival or departure. Depending on a vessel’s draft and the harbor’s depth, some vessels may be able to transit only at high tide. If this is this case, it is critically im￾portant to determine the time and range of the tide correctly. The magnitude and direction of the current will give the navigator some idea of the set and drift the vessel will experience during the transit. This will allow him to plan in advance for any potential current effects in the vicinity of navigation hazards. 803. Weather The navigator should obtain a weather report covering the route which he intends to transit. This will allow him to prepare for any heavy weather by stationing extra lookouts, adjusting his speed for poor visibility, and preparing for ra￾dar navigation. If the weather is thick, he may want to consider standing off the harbor until it clears. The navigator can receive weather information any number of ways. Military vessels receive weather reports from their parent squadrons prior to coming into port. Ma￾rine band radio carries continuous weather reports. Some vessels are equipped with weather facsimile machines. Some navigators carry cellular phones to reach shoreside personnel and harbor control; these can be used to get weather reports. However he obtains the information, the navigator should have a good idea of the weather where he will be piloting. 804. The Piloting Brief Assemble the entire navigation team for a piloting brief prior to entering or leaving port. The vessel’s captain and navigator should conduct the briefing. All navigation and bridge personnel should attend. The pilot, if he is already on board, should also attend. If the pilot is not onboard when the ship’s company is briefed, the navigator should imme￾diately brief him when he embarks. The pilot must know the ship’s maneuvering characteristics before entering re￾stricted waters. The briefing should cover, as a minimum, the following: • Detailed Coverage of the Track Plan: Go over the planned route in detail. Use the prepared and ap￾proved chart as part of this brief. Concentrate especially on all the NAVAIDS and soundings which are being used to indicate danger. Cover the buoyage system in use and the port’s major NAVAIDS. Point out the radar NAVAIDS for the radar operator. Often, a Fleet Guide or Sailing Directions will have pictures of a port’s NAVAIDS. This is especially important for the piloting party that has never transited this par￾ticular port before. If no pictures are available, consider stationing a photographer to take some for submission to DMAHTC. • Harbor Communications: Discuss the bridge-to bridge radio frequencies used to raise harbor control. Discuss what channel the vessel is supposed to monitor on its passage into port and the port’s communication protocol. • Duties and Responsibilities: Each member of the pi￾loting team must have a thorough understanding of his duties and responsibilities. He must also under￾stand how his part fits into the scheme of the whole

124PILOTINGThe radar plotter, for example, must know if radarvessel's SOA.The thicker the weather,the more slowlythe vessel must proceed.Therefore,ifheavyfog orrainwill betheprimaryor secondary source offix infor-mation.Thebearing recorder must know what fixisintheforecast.thenavigatormustadvancethetimeinterval thenavigator is planning to use.Eachpersonhewasplanningto leavefortheharborentrance.must be thoroughly briefed on his job; there is littleMooring Procedures: The navigator must take moretime for questions once the vessel enters the channel.than distance intoaccount when calculating howlong805.VoyagePlanningToTheHarbor Entranceit will take him to pilot to his mooring.If the vessel(Inbound Vessel Only)needsatug,thatwillsignificantlyincreasethetimeallottedtopiloting.Similarly,pickingup (inbound)orThe vessel's planned estimated time of arrival (ETA) atdroppingoff(outbound)apilotaddstimetothetransitits moorings determines the vessel's course and speed to theIt is betterto allowamarginforerrorwhentrying toharborentrance.Arrivingatthemooringsiteontimemaybeadd up all thetime delays caused by theseprocedures.important inabusyportwhichoperates itsportservices onaIt is always easierto avoid arriving early by slowingtight schedule.Therefore, it is important to conduct harbor ap-down than it is to make up lost time by speeding up.proach voyage planning accurately. Take the ETA at theTime to Find the Harbor Entrance: Depending on themooring and subtractfrom that the time it will taketonavigatethe harbor to the pier.The resulting time is when you must ar-sophisticationof his vessel'snavigation suite,anavigatorrive at the harbor entrance.Next, measure the distancemayrequiresometimetofind theharborentrance.This isbetweenthevessel'spresentlocationandtheharborentranceseldom a problem with warships and largemerchant ves-Determine the speed of advance (SOA)the vessel will usetosels, both of which carry sophisticated electronicmakethetransittotheharbor.Usethedistancetotheharbornavigation suites.However, it may be a consideration forand the SOAto calculatewhattimeto leavethepresentposi-theyachtsman relying solelyon dead reckoning and cetiontomakethemooringETAlestialnavigation.Considerthesefactors which mightaffect this decision:Shipping Density: Generally,the higher the shipping den-Weather:This is the single most important factor insity entering and exiting the harbor, the longer it will take toharbor approachplanningbecause it directlyaffectstheproceed intotheharborentrance safelyTRANSITIONTOPILOTING806. Stationing The Piloting Teamderstand the relationship between the pilot and thecaptain.The pilot is perhaps the captain's most impor-Approximatelyonehourpriortoleavingportorenteringtantnavigationadvisor:often,thecaptainwilldefertorestricted waters,station thepilotingteam.The number andhis recommendations when navigating an unfamiliartypeof personnel availableforthepiloting team depend onharbor.The pilot, too, bears some responsibility for thethevessel.ANavywarship,forexample,hasmorepeoplesafepassage ofthevessel:he can be censured for errorsavailableforpilotingthandoesamerchantman.Thereforeof judgment which causeaccidents.However,the pres-more thanoneofthe jobs listed belowmayhavetobefilledenceof apilotinno wayrelievesthecaptain of hisby a singleperson.Thepilotingteam should consist ofultimate responsibilityfor safenavigation.The pilotingteam works to support and advise the vessel's captain.The Captain: The captain is ultimately responsible forthe safe navigation ofhis vessel.His judgment regardingThe Officer of theDeck (Conning Officer):In Navynavigation isfinal.The piloting team acts to support thepiloting teams, neither the pilot or the captain usuallyhas the conn.The officer having the conn directs thecaptain, advising him so he can make informed deci-sions on handling his vessel.ship's movements by rudder and engine orders. Anoth-er officer of the ship's company usually fulfills thisThe Pilot:The pilot is usually the only member of thefunction The captain can take the conn immediatelypilotingteam notnormallya memberoftheship'scom-simply by issuing an order to the helm should an emer-pany.Many ports require a pilot, a federal or stategency arise.The conning officer of a merchant vessellicensed navigator who possesses extensive localcan be either the pilot, the captain, or another watch of-knowledgeoftheharbor.tobeonboardasthevesselficer.In any event, the officerhaving the conn must beclearly indicated in the ship's deck log at all times.Of-makes its harbor passage.The piloting team must un-

124 PILOTING The radar plotter, for example, must know if radar will be the primary or secondary source of fix infor￾mation. The bearing recorder must know what fix interval the navigator is planning to use. Each person must be thoroughly briefed on his job; there is little time for questions once the vessel enters the channel. 805. Voyage Planning To The Harbor Entrance (Inbound Vessel Only) The vessel’s planned estimated time of arrival (ETA) at its moorings determines the vessel’s course and speed to the harbor entrance. Arriving at the mooring site on time may be important in a busy port which operates its port services on a tight schedule. Therefore, it is important to conduct harbor ap￾proach voyage planning accurately. Take the ETA at the mooring and subtract from that the time it will take to navigate the harbor to the pier. The resulting time is when you must ar￾rive at the harbor entrance. Next, measure the distance between the vessel’s present location and the harbor entrance. Determine the speed of advance (SOA) the vessel will use to make the transit to the harbor. Use the distance to the harbor and the SOA to calculate what time to leave the present posi￾tion to make the mooring ETA. Consider these factors which might affect this decision: • Weather: This is the single most important factor in harbor approach planning because it directly affects the vessel’s SOA. The thicker the weather, the more slowly the vessel must proceed. Therefore, if heavy fog or rain is in the forecast, the navigator must advance the time he was planning to leave for the harbor entrance. • Mooring Procedures: The navigator must take more than distance into account when calculating how long it will take him to pilot to his mooring. If the vessel needs a tug, that will significantly increase the time al￾lotted to piloting. Similarly, picking up (inbound) or dropping off (outbound) a pilot adds time to the transit. It is better to allow a margin for error when trying to add up all the time delays caused by these procedures. It is always easier to avoid arriving early by slowing down than it is to make up lost time by speeding up. • Time to Find the Harbor Entrance: Depending on the sophistication of his vessel’s navigation suite, a navigator may require some time to find the harbor entrance. This is seldom a problem with warships and large merchant ves￾sels, both of which carry sophisticated electronic navigation suites. However, it may be a consideration for the yachtsman relying solely on dead reckoning and ce￾lestial navigation. • Shipping Density: Generally, the higher the shipping den￾sity entering and exiting the harbor, the longer it will take to proceed into the harbor entrance safely. TRANSITION TO PILOTING 806. Stationing The Piloting Team Approximately one hour prior to leaving port or entering restricted waters, station the piloting team. The number and type of personnel available for the piloting team depend on the vessel. A Navy warship, for example, has more people available for piloting than does a merchantman. Therefore, more than one of the jobs listed below may have to be filled by a single person. The piloting team should consist of: • The Captain: The captain is ultimately responsible for the safe navigation of his vessel. His judgment regarding navigation is final. The piloting team acts to support the captain, advising him so he can make informed deci￾sions on handling his vessel. • The Pilot: The pilot is usually the only member of the piloting team not normally a member of the ship’s com￾pany. Many ports require a pilot, a federal or state licensed navigator who possesses extensive local knowledge of the harbor, to be on board as the vessel makes its harbor passage. The piloting team must un￾derstand the relationship between the pilot and the captain. The pilot is perhaps the captain’s most impor￾tant navigation advisor; often, the captain will defer to his recommendations when navigating an unfamiliar harbor. The pilot, too, bears some responsibility for the safe passage of the vessel; he can be censured for errors of judgment which cause accidents. However, the pres￾ence of a pilot in no way relieves the captain of his ultimate responsibility for safe navigation. The piloting team works to support and advise the vessel’s captain. • The Officer of the Deck (Conning Officer): In Navy piloting teams, neither the pilot or the captain usually has the conn. The officer having the conn directs the ship’s movements by rudder and engine orders. Anoth￾er officer of the ship’s company usually fulfills this function. The captain can take the conn immediately simply by issuing an order to the helm should an emer￾gency arise. The conning officer of a merchant vessel can be either the pilot, the captain, or another watch of￾ficer. In any event, the officer having the conn must be clearly indicated in the ship’s deck log at all times. Of-

125PILOTINGten a single officer will have the deck and the conn.Plot Supervisors: Ideally,the piloting team shouldcon-However,sometimes a juniorofficer will takethe connsist oftwo plots: the primary plot and the secondary plot.fortraining.InthiscasedifferentofficerswillhavetheThenavigator should designate thetypeof navigationdeck and the conn.The officer who retains the deck re-that will be employed on theprimaryplot.All otherfixtains theresponsibilityfor the vessel's safe navigationsources should beplotted on the secondaryplot.Forex-ample,ifthe navigator designates visual piloting as theprimary fix method, lay down only visual bearings onThe Navigator:The vessel's navigator is the officerthe primary plot. Lay down all other fix sources (radar,directlyresponsibletothe ship's captainforthe safeelectronic.orsatellite)onthesecondarvplot.Thenavinavigation of the ship.He is the captain's principalgator can function as the primary plot supervisor.Anavigationadvisor.Thepilotingpartyworksforhimsenior.experiencedindividualshouldbeemplovedasaHechannels therequired informationdevelopedbythesecondary plot supervisor.The navigator should fre-pilotingpartytotheship's conningofficeronrecom-quentlycomparethepositionsplottedonbothplotsasamended courses, speeds, and turns.He also carefullycheck on the primary plot.looksaheadforpotential navigationhazardsandmakesappropriaterecommendations.Heis themost seniorThere are three major reasons for maintaining a prima-officer who devotes his effort exclusively to monitor-ry and secondary plot. First, as mentioned above, theingthenavigation picture.Thecaptain and theconningsecondaryfixsourcesprovideagoodcheckontheaccuraofficer areconcernedwith all aspects ofthepassage,cy of visual piloting. Large discrepancies between visualincluding contact avoidance and other necessary shipand radarpositionsmaypointouta problem withthevisu-evolutions (making up tugs, maneuvering alongside aal fixes that the navigator might not otherwise suspectsmall boat for personnel transfers, engineering evolu-Secondly,the navigator often must change the primarytions.andcoordinatingwithharborcontrolviaradiomeansofnavigationduringthetransit.Hemayinitiallforexample).Thenavigator,on theotherhand,focusesdesignatevisual bearings astheprimaryfix methodonlytosolely on safe navigation.It is his job to anticipate dan-havea sudden stormorfogobscure thevisual NAVAIDSIf he shifts theprimaryfix means to radar, he has a trackger and keep himself appraised of the navigationsituationatall times.history of the correlation between radar and visual fixesFinally,the piloting team oftenmust shift charts severaltimes duringthetransit.Whentheoldchart istaken offtheBearing Plotting Team: This team consists, ideally,plottingtable and before the new chart is secured, there isof three persons.The firstperson measures the bear-aperiodoftimewhennochartisinuse.Maintainingasec-ings.The second person records thebearings in anondary ploteliminatesthis complicationEnsure theofficial record book.Thethird person plots the bear-secondaryplot isnotshiftedpriortogettingthenewprima-ings.The more quickly and accurately this process isryplotchartdownonthecharttableInthiscasetherewillcompleted,thesoonerthenavigatorhasanaccuratealways be a chart availableon whichtopilot.Do not con-picture of the ship's position.The bearing taker shouldsider the primary chart shifed until the new chart isbe an experienced individual who has traversed theproperly secured and the plotter has transferred the last fixport beforeand who is familiar with the NAVAIDSfromthe original chartontothenewchart.He should take his round of bearings as quickly as pos-sible,minimizing any timedelayerrors in the resultingSatellite Navigation Operator: This operator normal-fix.The plotter should also be an experienced individ-ly works for the secondary plot supervisor.GPSual who can quickly and accurately lay down therequired bearings.The bearing recorder canbe one ofabsolute accuracywith SA operational is notsufficientthe junior members of the piloting team.formostpilotingapplications.However,thesecondaryplotshouldkeeptrackofGPSfixes.Iftheteamsloosesvisual bearings in the channel and no radar NAVAIDSTheRadar Operator:The radar operator has one ofare available, GPS maybe the most accuratefix sourcethemore difficult jobs of the team.The radar is as im-available.Thenavigatormusthavesomedataontheportant for collision avoidance as it is for navigation.comparisonbetween satellite positions andvisual posiTherefore,this operator musttime share"the radar betions over the history of the passage to use satellitetweenthesetwofunctions.Determiningtheamountofpositions effectively.The only way to obtain this datatime spent on thesefunctions falls withinthe judgmentis toplot satellite positions and compare theseposi-of the captain and the navigator.Iftheday is clear andtions to visual positions throughout the harbor passage.thetraffic heavy,the captain maywant to use theradarmostly for collision avoidance.As the weather wors-Fathometer Operator:Run the fathometer continu-ens,obscuringvisualNAVAIDS,the importanceofradar for safe navigation increases.The radar operatorously and station an operator tomonitor it.Do not relymust be given clear guidance on how the captain andonaudiblealarmstokeyvourattentiontothiscriticallynavigator want the radar to beoperated.importantpilotingtool.Thefathometeroperatormust

PILOTING 125 ten a single officer will have the deck and the conn. However, sometimes a junior officer will take the conn for training. In this case, different officers will have the deck and the conn. The officer who retains the deck re￾tains the responsibility for the vessel’s safe navigation. • The Navigator: The vessel’s navigator is the officer directly responsible to the ship’s captain for the safe navigation of the ship. He is the captain’s principal navigation advisor. The piloting party works for him. He channels the required information developed by the piloting party to the ship’s conning officer on recom￾mended courses, speeds, and turns. He also carefully looks ahead for potential navigation hazards and makes appropriate recommendations. He is the most senior officer who devotes his effort exclusively to monitor￾ing the navigation picture. The captain and the conning officer are concerned with all aspects of the passage, including contact avoidance and other necessary ship evolutions (making up tugs, maneuvering alongside a small boat for personnel transfers, engineering evolu￾tions, and coordinating with harbor control via radio, for example). The navigator, on the other hand, focuses solely on safe navigation. It is his job to anticipate dan￾ger and keep himself appraised of the navigation situation at all times. • Bearing Plotting Team: This team consists, ideally, of three persons. The first person measures the bear￾ings. The second person records the bearings in an official record book. The third person plots the bear￾ings. The more quickly and accurately this process is completed, the sooner the navigator has an accurate picture of the ship’s position. The bearing taker should be an experienced individual who has traversed the port before and who is familiar with the NAVAIDS. He should take his round of bearings as quickly as pos￾sible, minimizing any time delay errors in the resulting fix. The plotter should also be an experienced individ￾ual who can quickly and accurately lay down the required bearings. The bearing recorder can be one of the junior members of the piloting team. • The Radar Operator: The radar operator has one of the more difficult jobs of the team. The radar is as im￾portant for collision avoidance as it is for navigation. Therefore, this operator must “time share” the radar be￾tween these two functions. Determining the amount of time spent on these functions falls within the judgment of the captain and the navigator. If the day is clear and the traffic heavy, the captain may want to use the radar mostly for collision avoidance. As the weather wors￾ens, obscuring visual NAVAIDS, the importance of radar for safe navigation increases. The radar operator must be given clear guidance on how the captain and navigator want the radar to be operated. • Plot Supervisors: Ideally, the piloting team should con￾sist of two plots: the primary plot and the secondary plot. The navigator should designate the type of navigation that will be employed on the primary plot. All other fix sources should be plotted on the secondary plot. For ex￾ample, if the navigator designates visual piloting as the primary fix method, lay down only visual bearings on the primary plot. Lay down all other fix sources (radar, electronic, or satellite) on the secondary plot. The navi￾gator can function as the primary plot supervisor. A senior, experienced individual should be employed as a secondary plot supervisor. The navigator should fre￾quently compare the positions plotted on both plots as a check on the primary plot. There are three major reasons for maintaining a prima￾ry and secondary plot. First, as mentioned above, the secondary fix sources provide a good check on the accura￾cy of visual piloting. Large discrepancies between visual and radar positions may point out a problem with the visu￾al fixes that the navigator might not otherwise suspect. Secondly, the navigator often must change the primary means of navigation during the transit. He may initially designate visual bearings as the primary fix method only to have a sudden storm or fog obscure the visual NAVAIDS. If he shifts the primary fix means to radar, he has a track history of the correlation between radar and visual fixes. Finally, the piloting team often must shift charts several times during the transit. When the old chart is taken off the plotting table and before the new chart is secured, there is a period of time when no chart is in use. Maintaining a sec￾ondary plot eliminates this complication. Ensure the secondary plot is not shifted prior to getting the new prima￾ry plot chart down on the chart table. In this case, there will always be a chart available on which to pilot. Do not con￾sider the primary chart shifted until the new chart is properly secured and the plotter has transferred the last fix from the original chart onto the new chart. • Satellite Navigation Operator: This operator normal￾ly works for the secondary plot supervisor. GPS absolute accuracy with SA operational is not sufficient for most piloting applications. However, the secondary plot should keep track of GPS fixes. If the teams looses visual bearings in the channel and no radar NAVAIDS are available, GPS may be the most accurate fix source available. The navigator must have some data on the comparison between satellite positions and visual posi￾tions over the history of the passage to use satellite positions effectively. The only way to obtain this data is to plot satellite positions and compare these posi￾tions to visual positions throughout the harbor passage. • Fathometer Operator: Run the fathometer continu￾ously and station an operator to monitor it. Do not rely on audible alarms to key your attention to this critically important piloting tool. The fathometer operator must

126PILOTINGknow the warning and danger soundings for the areaOncethenavigatorverifiestheaboveequipmentis inplacethe vessel is transiting. Most fathometers can displayhetapes downthecharts on thechart table.ifmore than oneeither total depth of water or depth under thekeel.Setchart isrequired for the transit, tape the charts ina stack such thatthe fathometer to display depth underthekeel.ThetheplotterworksfromthetoptothebottomofthestackThisnavigator must check the sounding at each fix andminimizes the time required to shift the chart during the transitIf the plotter is using a PMP,align the arm ofthePMP with anycomparethatvaluetothechartedsounding.Adiscrep-ancy between these values is cause for immediatemeridian of longitude on the chart. While holding the PMP armaction to take another fix and check the ship's position.stationary, adjust the PMP to read 000.0°T.This procedure cal-ibrates the PMPto thechart in use.Perform this alignment every807.PlotSetuptime the piloting team shifts charts.Be careful nottofoldunderany important informationwhen folding the chart on the chart table.Ensure the chart'sOncethepilotingteam is onstation,ensuretheprimarydistance scale,theentiretrack,and all important warningandsecondaryplothavethefollowinginstrumentsinformation arevisible.:Dividers: Dividers are used to measure distances be-Energize andtestall electronic navigationequipmentifnot already in operation.This includes theradarand thetween points on the chart.GPS receiver.Energize and test the fathometer.Ensuretheentire electronic navigation suite isoperatingproperlyprior:Compasses: Compasses are used to plot range arcsto entering restricted watersfor radar LOP's.Beam compasses are used when therangearc exceedsthespread of a conventional com-808. Evolutions Prior To Pilotingpass.Both should be available at both plots.The navigator should always accomplish thefollowing:Bearing Measuring Devices:Several types ofevolutions priortopiloting:bearing measuring devices are available.The pre-ferreddevice istheparallel motionplotter(PMP).Testing the Shaft on the Main Engines in theused in conjunction with a drafting table.Other-wise, use parallel rulers or rolling rulers with theAstern Direction: This ensures that the ship can an-chart's compass rose.Finally,the plotter can use aswer a backing bell. If the ship is entering port, noone arm protractor.Theplotter should use the de-special precautions are required prior to this test.Ifthevice with which hecan work the most quickly andship is tied up at the pier preparing to get underwayaccurately.exerciseextremecautiontoensurenowayisplacedon the ship whiletestingthemain engines..Sharpened Pencils and Erasers: Ensure an ade-·Making the Anchor Ready for Letting Go: Makequate supply of pencils is available. There isgenerally not time to sharpen one if it breaks in thetheanchor ready for letting go and station a watch-middle of the transit, so have several sharpened pen-standerin direct communications withthebridge atcils available at the plot.the anchor windlass.Be prepared to dropanchor im-mediately when piloting if required to keep from:Three Arm Protractor:This protractor is used todrifting too closeto a navigation hazard.plot relative bearings and sextant horizontal anglesshould the true bearing source fail during the transit..Calculate GyroError:An errorofgreater than 1.0oT indicates a gyro problem which should be investi-: Fischer Radar Plotting Templates: Fischer plot-gated priorto piloting.There are several waystodetermine gyro error:tingiscoveredinChapter13.Theplottingtemplatesfor this technique should be stacked near the radar1.Compare the gyro reading with a known accu-repeater.rate headingreferencesuchasaninertialnavigator. The difference in the readings is the:Time-Speed-Distance Calculator: Given two ofgyro error.the three unknowns (between time, speed, and dis-tance),this calculator allowsforrapid computationof the third.2.Mark the bearing ofa charted range as the rangeNAVAID's come into lineand comparethegyro:Tide and Current Graphs: Post thetide and currentbearing with thechartedbearing.Thedifferenceis thegyro error.graphs near the primary plot for easy reference dur-ing the transit. Give a copy of the graphs to the3.Prior to getting underway,plot a dockside fix usingconning officer and thecaptain

126 PILOTING know the warning and danger soundings for the area the vessel is transiting. Most fathometers can display either total depth of water or depth under the keel. Set the fathometer to display depth under the keel. The navigator must check the sounding at each fix and compare that value to the charted sounding. A discrep￾ancy between these values is cause for immediate action to take another fix and check the ship’s position. 807. Plot Setup Once the piloting team is on station, ensure the primary and secondary plot have the following instruments: • Dividers: Dividers are used to measure distances be￾tween points on the chart. • Compasses: Compasses are used to plot range arcs for radar LOP’s. Beam compasses are used when the range arc exceeds the spread of a conventional com￾pass. Both should be available at both plots. • Bearing Measuring Devices: Several types of bearing measuring devices are available. The pre￾ferred device is the parallel motion plotter (PMP) used in conjunction with a drafting table. Other￾wise, use parallel rulers or rolling rulers with the chart’s compass rose. Finally, the plotter can use a one arm protractor. The plotter should use the de￾vice with which he can work the most quickly and accurately. • Sharpened Pencils and Erasers: Ensure an ade￾quate supply of pencils is available. There is generally not time to sharpen one if it breaks in the middle of the transit, so have several sharpened pen￾cils available at the plot. • Three Arm Protractor: This protractor is used to plot relative bearings and sextant horizontal angles should the true bearing source fail during the transit. • Fischer Radar Plotting Templates: Fischer plot￾ting is covered in Chapter 13. The plotting templates for this technique should be stacked near the radar repeater. • Time-Speed-Distance Calculator: Given two of the three unknowns (between time, speed, and dis￾tance), this calculator allows for rapid computation of the third. • Tide and Current Graphs: Post the tide and current graphs near the primary plot for easy reference dur￾ing the transit. Give a copy of the graphs to the conning officer and the captain. Once the navigator verifies the above equipment is in place, he tapes down the charts on the chart table. If more than one chart is required for the transit, tape the charts in a stack such that the plotter works from the top to the bottom of the stack. This minimizes the time required to shift the chart during the transit. If the plotter is using a PMP, align the arm of the PMP with any meridian of longitude on the chart. While holding the PMP arm stationary, adjust the PMP to read 000.0°T. This procedure cal￾ibrates the PMP to the chart in use. Perform this alignment every time the piloting team shifts charts. Be careful not to fold under any important information when folding the chart on the chart table. Ensure the chart’s distance scale, the entire track, and all important warning information are visible. Energize and test all electronic navigation equipment, if not already in operation. This includes the radar and the GPS receiver. Energize and test the fathometer. Ensure the entire electronic navigation suite is operating properly prior to entering restricted waters. 808. Evolutions Prior To Piloting The navigator should always accomplish the following evolutions prior to piloting: • Testing the Shaft on the Main Engines in the Astern Direction: This ensures that the ship can an￾swer a backing bell. If the ship is entering port, no special precautions are required prior to this test. If the ship is tied up at the pier preparing to get underway, exercise extreme caution to ensure no way is placed on the ship while testing the main engines. • Making the Anchor Ready for Letting Go: Make the anchor ready for letting go and station a watch￾stander in direct communications with the bridge at the anchor windlass. Be prepared to drop anchor im￾mediately when piloting if required to keep from drifting too close to a navigation hazard. • Calculate Gyro Error: An error of greater than 1.0° T indicates a gyro problem which should be investi￾gated prior to piloting. There are several ways to determine gyro error: 1. Compare the gyro reading with a known accu￾rate heading reference such as an inertial navigator. The difference in the readings is the gyro error. 2. Mark the bearing of a charted range as the range NAVAID’s come into line and compare the gyro bearing with the charted bearing. The difference is the gyro error. 3. Prior to getting underway, plot a dockside fix using

127PILOTINGat least three lines of position. The three LOP'sminutes inthefathometerlog.Record allfathometersetshould intersect at a point. Their intersecting in atings that could affect the sounding display."cocked hat"indicates a gyro error.Incrementally.Deck Log:This log is the legal record of the passage.adjusteach visual bearingbythe same amountandin the same direction until the fix plots as a pinpointRecord all ordered course and speed changes. Record allThetotal corretionrequiredtoeliminate the cockedthe navigator's recommendations and whether the navi-hat is the gyro error.gator concurs with theactions of the conning officerRecordallbuovspassedandtheshiftbetweendifferent4.Measure a celestial body's azimuth, a celestialRulesoftheRoad.Record thenameandembarkationofbody's amplitude,or Polaris'azimuth withtheany pilot. Record who has the conn at all times. Recordgyro,and then comparethe measured valuewithanycasualtyorimportantevent.Thedecklogcombineda value computed from the Sight Reduction ta-withthebearing logshould constituteacompleterecordblesortheNautical Almanac.Thesemethods areofthepassage.covered in detail in Chapter17.810.Harbor Approach (Inbound Vessels Only)Report the magnitude and direction of the gyroThe piloting team must make the transition from coastalerrortothe navigator and captain.Thedirection of theerror is determined bythe relativemagnitude of thenavigationtopiloting smoothlyasthevessel approachesre-gyro reading and the value against which it is com-stricted waters.Thereisnorigid demarcation betweenpared.Whenthe compass is least,theerror is east.coastalnavigationandpiloting.OftenvisualNAVAIDSareConverselywhenthecompassisbest,theerroriswest.visiblemilesfrom shore wherehyperbolic and satellitenavi-gationprovides sufficientabsoluteaccuracytoensureship809.Recordssafety.The navigator should take advantage of this overlapwhen approaching the harbor.Plot hyperbolic, satellite, andEnsure the following records are assembled and per-visual fixes concurrentlyon theprimaryplot,ensuring thepi-sonnelassigned to completethempriorto piloting:loting team has correctly identified NAVAIDS and iscomfortablysettling intoa pilotingroutine.Once thevesselBearing Record Book:Thebearingrecorders foris closeenoughto the shore such that sufficient NAVAIDSthe primary and secondary plots should record all the(at leastthreewith sufficientbearing spread)becomevisible,bearings used on their plot during the entire transit.the navigator should order visual bearings only for the prima-Thebooks should clearly list what NAVAIDS areryplotand shiftplotting all otherfixestothesecondaryplotTake advantage of the coastal navigation and pilotingbeingused andwhatmethod ofnavigationwasbeingused on their plot. In practice,theprimary bearingoverlapto shorten thefix interval graduallyThe navigatorbook will contain mostly visual bearings and the secmust use his judgment in adjusting these transition fix inter-ondary bearingbook will contain mostlyradarvals.If the ship is steaming inbound directly towards therangesandbearings.shore, set a fix interval such that two fix intervals lie be-tween the vessel and the nearest danger. Prior to entering. Fathometer Log: In restricted waters, monitor sound-intorestricted waters,thepilotingteam should beplottingings continuously and record soundings every fivevisual fixes at three minute intervals.FIXINGAVESSEL'SPOSITIONWHILEPILOTINGThe navigator now has his charts prepared; his team811.Fixing The Ship's Position ByTwo Or Morebriefed,equipped,and on station;hisequipmenttested,andLinesOfPositionhis record books distributed.He is now ready to beginThe intersection ofat least two LOP's constitutes a fix.pilotingHowever, always use three LOP's if three are availableSafe navigation while piloting requires frequent fixingSomeof themost commonlyused methods of obtainingof the ship's position.The next sections will discuss theLOP'sarediscussedbelow:three major methodologies used to fix a ship's positionwhenpiloting:crossinglinesofposition,copying satelliteorFixbyTwoBearingLines:Theplotterlays downtwoLorandata,oradvancingasinglelineofposition.Usingoneor morebearing linesfrom charted NAVAIDS.This ismethod does not exclude using other methods.The navigathemostcommonandoftenthemostaccuratewaytotormustobtainasmuchinformationaspossibleandemployasmanyofthesemethodsaspractical whilepiloting.fixa vessel'sposition.Theplottercan alsolay down

PILOTING 127 at least three lines of position. The three LOP’s should intersect at a point. Their intersecting in a “cocked hat” indicates a gyro error. Incrementally adjust each visual bearing by the same amount and in the same direction until the fix plots as a pinpoint. The total corretion required to eliminate the cocked hat is the gyro error. 4. Measure a celestial body’s azimuth, a celestial body’s amplitude, or Polaris’ azimuth with the gyro, and then compare the measured value with a value computed from the Sight Reduction ta￾bles or the Nautical Almanac. These methods are covered in detail in Chapter 17. Report the magnitude and direction of the gyro error to the navigator and captain. The direction of the error is determined by the relative magnitude of the gyro reading and the value against which it is com￾pared. When the compass is least, the error is east. Conversely, when the compass is best, the error is west. 809. Records Ensure the following records are assembled and per￾sonnel assigned to complete them prior to piloting: • Bearing Record Book: The bearing recorders for the primary and secondary plots should record all the bearings used on their plot during the entire transit. The books should clearly list what NAVAIDS are being used and what method of navigation was being used on their plot. In practice, the primary bearing book will contain mostly visual bearings and the sec￾ondary bearing book will contain mostly radar ranges and bearings. • Fathometer Log: In restricted waters, monitor sound￾ings continuously and record soundings every five minutes in the fathometer log. Record all fathometer set￾tings that could affect the sounding display. • Deck Log: This log is the legal record of the passage. Record all ordered course and speed changes. Record all the navigator’s recommendations and whether the navi￾gator concurs with the actions of the conning officer. Record all buoys passed, and the shift between different Rules of the Road. Record the name and embarkation of any pilot. Record who has the conn at all times. Record any casualty or important event. The deck log combined with the bearing log should constitute a complete record of the passage. 810. Harbor Approach (Inbound Vessels Only) The piloting team must make the transition from coastal navigation to piloting smoothly as the vessel approaches re￾stricted waters. There is no rigid demarcation between coastal navigation and piloting. Often visual NAVAIDS are visible miles from shore where hyperbolic and satellite navi￾gation provides sufficient absolute accuracy to ensure ship safety. The navigator should take advantage of this overlap when approaching the harbor. Plot hyperbolic, satellite, and visual fixes concurrently on the primary plot, ensuring the pi￾loting team has correctly identified NAVAIDS and is comfortably settling into a piloting routine. Once the vessel is close enough to the shore such that sufficient NAVAIDS (at least three with sufficient bearing spread) become visible, the navigator should order visual bearings only for the prima￾ry plot and shift plotting all other fixes to the secondary plot. Take advantage of the coastal navigation and piloting overlap to shorten the fix interval gradually. The navigator must use his judgment in adjusting these transition fix inter￾vals. If the ship is steaming inbound directly towards the shore, set a fix interval such that two fix intervals lie be￾tween the vessel and the nearest danger. Prior to entering into restricted waters, the piloting team should be plotting visual fixes at three minute intervals. FIXING A VESSEL’S POSITION WHILE PILOTING The navigator now has his charts prepared; his team briefed, equipped, and on station; his equipment tested; and his record books distributed. He is now ready to begin piloting. Safe navigation while piloting requires frequent fixing of the ship’s position. The next sections will discuss the three major methodologies used to fix a ship’s position when piloting: crossing lines of position, copying satellite or Loran data, or advancing a single line of position. Using one method does not exclude using other methods. The naviga￾tor must obtain as much information as possible and employ as many of these methods as practical while piloting. 811. Fixing The Ship’s Position By Two Or More Lines Of Position The intersection of at least two LOP’s constitutes a fix. However, always use three LOP’s if three are available. Some of the most commonly used methods of obtaining LOP’s are discussed below: • Fix by Two Bearing Lines: The plotter lays down two or more bearing lines from charted NAVAIDS. This is the most common and often the most accurate way to fix a vessel’s position. The plotter can also lay down

128PILOTINGFix by Two Ranges: The navigator can plot a fix con-sisting ofthe intersection oftwo range arcs from chartedobjects.Hecanobtainanobjectsrangeinseveralways:1. Radar Ranges: See Figure 81lb. The plotter laysdownarangearcfrom asmall islandandarangearcfrom aprominentpointon shore.The intersectionofthe range arcs constitutes a fix. The navigator canplot ranges from any point on the radar scope which0835he can correlate on his chart. This is the most conve-nient and accurate way to obtain an object's range.If a choice is available between fixed radar NA-VAIDS and low lying land, choose the fixedNAVAID.Thiswill minimizeerrors caused byus-ing low lying land subject to large tidal ranges.2. Stadimeter Ranges: Given a known height of a NA-VAID,use a stadimeter to determine the range.Though most often used to determine the distance toa surface contact, a stadimeter can be used to deter-mine an object's range. See Figure 81lc for aFigure 8lla.Afix by twobearing linesrepresentation of the geometry involved. Generally,stadimeters contain a height scale on which is set thebearings to a NAVAID and a bearing to the tangent ofheight ofthe object.The observerthen directs his lineabodyof land.SeeFigure81la.Theintersectionofof sightthrough the stadimeter tothebase ofthe ob-these linesconstitutes afix.Plottingbearinglinesfromject being observed. Finally, he adjusts thechartedbuoys istheleastpreferredmethodoffixingbystadimeter's range index until the object's top reflec-twobearinglinesbecausethebuoyschartedpositiontion is"brought down"to the visible horizon. Readis only approximate. Tangent LOPs to land areas mustthe object's range offofthe stadimeter's range index.be taken carefully to get an accurate line, particularlyat long ranges; charted NAVAIDS are preferred.3.Sextant VerticalAngles:Measure thevertical an-gle from the top of the NAVAID to the waterlinebelowtheNAVAID.EnterTable16todeterminethe distance of theNAVAID.The navigator mustO1Figure 811b. A fix by two radar ranges.Figure 81lc.Principleof stadimeteroperation

128 PILOTING bearings to a NAVAID and a bearing to the tangent of a body of land. See Figure 811a. The intersection of these lines constitutes a fix. Plotting bearing lines from charted buoys is the least preferred method of fixing by two bearing lines because the buoy’s charted position is only approximate. Tangent LOPs to land areas must be taken carefully to get an accurate line, particularly at long ranges; charted NAVAIDS are preferred. • Fix by Two Ranges: The navigator can plot a fix con￾sisting of the intersection of two range arcs from charted objects. He can obtain an object’s range in several ways: 1. Radar Ranges: See Figure 811b. The plotter lays down a range arc from a small island and a range arc from a prominent point on shore. The intersection of the range arcs constitutes a fix. The navigator can plot ranges from any point on the radar scope which he can correlate on his chart. This is the most conve￾nient and accurate way to obtain an object’s range. If a choice is available between fixed radar NA￾VAIDS and low lying land, choose the fixed NAVAID. This will minimize errors caused by us￾ing low lying land subject to large tidal ranges. 2. Stadimeter Ranges: Given a known height of a NA￾VAID, use a stadimeter to determine the range. Though most often used to determine the distance to a surface contact, a stadimeter can be used to deter￾mine an object’s range. See Figure 811c for a representation of the geometry involved. Generally, stadimeters contain a height scale on which is set the height of the object. The observer then directs his line of sight through the stadimeter to the base of the ob￾ject being observed. Finally, he adjusts the stadimeter’s range index until the object’s top reflec￾tion is “brought down” to the visible horizon. Read the object’s range off of the stadimeter’s range index. 3. Sextant Vertical Angles: Measure the vertical an￾gle from the top of the NAVAID to the waterline below the NAVAID. Enter Table 16 to determine the distance of the NAVAID. The navigator must Figure 811a. A fix by two bearing lines. Figure 811b. A fix by two radar ranges. Figure 811c. Principle of stadimeter operation