Raymarine i70 - Point Speed Calibration; Nautical Measured Mile Markers

1PointSpeedCalibration
Formostinstallationsa1PointSpeedCalibrationis
allthatisrequired.
Prerequisites:
•ForbestresultsSOGdatashouldbeavailable,or
analternativemethodofestimatingvesselspeed
mustbeused(e.g.vesselspeedcanbeestimated
usingNauticalMeasuredMileMarkersorsimilar
landmarksofaknowndistanceapart).
•Youwillneedtobeunderway,withsufcientspace
tomaneuverunhindered.
•Inordertoachieveaccurateresults,water
conditionsmustbecalmwithzerotideandzero
current.
Fromafavoritepage:
1.SelectMenu.
2.SelectSet-up.
3.SelectTransducersSet-up.
4.SelectContinue.
Theinstrumentdisplaywillsearchforanddisplay
alistofconnecteddevices.(i.e.iTC-5,DSTor
transducerpod)
5.Selectthedevicethatthetransducer(s)youare
calibratingareconnectedto.
Alistofavailabletransducerdataisdisplayed,
6.*SelectSpeed.
Important:*SteponlyapplicabletoiTC-5.
7.SelectSpeedCalibration.
8.SelectAdjustspeedup/down.
The1PointSpeedCalibrationpageisdisplayed.
1.SOGspeedreading
2.Currentspeedreading
IfSOGisnotavailablethentheSOGvaluewill
displaydashes.
9.Accelerateyourvesseltoasteady,typical
cruisingspeed.
10.UsetheUpandDownbuttonstoadjustthe
currentspeedreadingsothatitmatchestheSOG
readingormatchesyourestimatedspeed.
11.SelectDonewhenbothvaluesarethesame.
Thecalibrationcompletepageisdisplayed.
12.SelectOk.
IfyouexperiencesignicantdeviationbetweenSOG
andlogspeedreadingsatdifferentvesselspeeds
thenaSpeedRunCalibrationshouldbeperformed.
RefertothePerformingaSpeedRunCalibration
usingSOGsectionfordetails.
Nauticalmeasuredmilemarkers
WhenneitherSOGdataoranyotherreliablemeans
ofestimatingSpeedThroughtheWater(STW)is
available,NauticalMeasuredMileMarkerscan
beusedtohelpcalibrateLogSpeed.Nautical
measuredmilemarkersareidentiedbytwopairsof
postsortowers.Thedistancebetweeneachpairof
markersis1nauticalmile.
Eachmarkerinapairisseparatedbydistanceand
elevationfromitspartner.Thefrontmarkeriscloser
tothewaterandshorterthanthemarkerbehindit.
Markers—sideview
1.Frontmarker
2.Rearmarker
Whenthe2markersappearverticallyaligned
thevesselisonthecorrectrangelinetobegina
measuredmilerun.
Markeralignment
1.Leftofrangeline
2.Onrangeline
3.Rightofrangeline
Thevesselshouldalreadybeattopspeedandas
therstpairofmarkersappearalignedastopwatch
shouldbestarted,whenthevesselpassesthe
secondpairofalignedmarkersthestopwatchis
stopped.
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