ItemDescription
1
Safetarget
2Losttarget
3Dangeroustarget
4Targetbeingacquired
Safetynotices
MARPAcanimprovecollisionavoidancewhenusedwisely.Itis
yourresponsibilitytoexercisecommonprudenceandnavigational
judgement.
Thereareconditionswhereacquiringatargetmaybecomedifcult.
Thesesameconditionsmaybeafactorinsuccessfullytrackinga
target.Someoftheconditionsare:
•Thetargetechoisweak.Thetargetisveryclosetoland,buoys
orotherlargetargets.
•Thetargetoryourownvesselismakingrapidmanoeuvres.
•Choppyseastateconditionsexistandthetargetisburiedin
excessiveseaclutterorindeepswells.
•Choppyseastateconditionsexistyieldingpoorstability;own
vessel’sheadingdataisveryunstable.
•Inadequateheadingdata.
Symptomsofsuchconditionsinclude:
•targetacquisitionisdifcultandtheMARPAvectorsareunstable;
•thesymbolwandersawayfromthetarget,locks-ontoanother
target,orchangestoalostsymboltarget.
Inthesecircumstances,targetacquisitionandtrackingmayneedto
bere-initiatedandinsomecasesmightbeimpossibletomaintain.
Betterqualityheadingdatamightimproveperformanceinthese
circumstances.
HowaMARPAriskisassessed
Eachtargetismonitoredtoascertainwhetheritwillbewithina
certaindistancefromyourvesselwithinacertaintime.Ifso,the
targetisdesignatedasdangerous,andanaudiblewarningis
soundedandawarningdisplayed.Thetargetsymbolchangesto
thedangeroustargetsymbolandashestoindicatethatitisa
dangeroustarget.Acknowledgingthealarmwillremovethewarning.
Ifatargetislost,eitherbecausetheMARPAsoftwarehaslost
contactwithit,orbecauseithasmovedoutofrange,anaudible
alarmissoundedandanon-screenwarningappears.Theon-screen
symbolwillchangetothetargetlostsymbol.Acknowledgingthe
warningwillsilencethealarmandremovetheon-screenwarning
andthetargetlostsymbol.
EffectiverangeforMARPAtargets
MARPAtargetacquisitionisonlyavailableatradarrangescalesof
upto12nm,althoughtrackingcontinuesatallranges.
Ifyouchangetoasmallerrangescale,targetsmaybebeyondthe
rangeofyourradarscannerandwillbelost.Insuchcases,an
on-screenwarningindicatesthatthetargetisoff-screen.
166e7/e7D—Userreference
To Next Page
Loading...
