Raymarine LIGHTHOUSE 4 - Page 60

2.Maximumheightfromwaterline
3.W
aterline
4.[Minimumsafeheight]
Minimumsafeheightcalculationguidance
Theinformationbelowisprovidedforguidanceonlyandisnotexhaustive.
Someinfluencingfactorscanbeuniquetocertainvesselsand/orareasof
waterandmaynotbelistedbelow.Y oushouldensureyouaccountforALL
factorsthatapplytoyourcurrentsituationwhenmakingcalculations.
Someofthefactorsthatcaninfluencevesselheightareshownbelow:
•Vesseldisplacement(weight)—Avessel’sheight(fromthewaterline)will
decreasewhenitisfullyladencomparedwithitsunladendisplacement.
•Watertype—Avessel’sheightwilldecreasebyapproximately2%to3%in
freshwatercomparedtoseawater.
Someofthefactorsthatshouldbetakenintoaccountwhencalculating
asafetymarginare:
•Vesselmaneuveringcharacteristics—Avessel’sheightchangesdue
tosquat,trim,roll,pitchandheave.
•Chartaccuracy—Theelectronicchartdatamaynotbeaccurateormay
havechangedsincethelastsurvey.
•Weatherconditions—Lowairpressure,andprevailingwindstrength
anddirectioncanaffectwaterlevel.
Minimumsafewidth
Duringthestartupwizardyoucansetaminimumsafewidthforyourvessel.
Theminimumsafewidthcanalsobeaddedorchangedatanytimefromthe
[Boatdetails]settingmenu:[Homescreen>Settings>Boatdetails].
Asuitablevalueforminimumsafewidthcanbeestablishedbyidentifying
yourvessel’smaximumwidthandaddingasafetymargintoeachside.
•Maximumwidth—Takenfromthewidestpoint.
•Safetymargin—Anadequateclearancetoeithersideofthevessel.)
1.Portsafetymargin
2.Maximumvesselwidth(beam)
3.Starboardsafetymargin
4.[Minimumsafewidth]
Minimumsafewidthcalculationguidance
Theinformationbelowisprovidedforguidanceonlyandisnotexhaustive.
Someinfluencingfactorscanbeuniquetocertainvesselsand/orareasof
waterandmaynotbelistedbelow.Y oushouldensureyouaccountforALL
factorsthatapplytoyourcurrentsituationwhenmakingcalculations.
Someofthefactorsthatshouldbetakenintoaccountwhencalculating
aSafetyMarginare:
•Vesselmaneuveringcharacteristics—Avessel’srequiredclearancewill
increaseduetoroll.
•Chartaccuracy—Theelectronicchartdatamaynotbeaccurateormay
havechangedsincelastsurveyed.
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