Specifications

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
DigitalSelectiveCalling(DSC),allowsboaterstoinstantlysendan
automaticallyformatteddistressalerttotheCoastGuardorother
rescueauthorityanywhereintheworldDigitalSelectiveCallingalsoal-
lowsboaterstoinitiateorreceivedistress,urgency,safety,androutine
radiotelephonecallstoorfromanysimilarlyequippedvesselorshore
station,withoutrequiringeitherpartytobeneararadioloudspeaker
DSCactslikethedialandbellofatelephone,allowingyouto“direct
dial”and“ring”otherradios,orallowingothersto“ring”you,without
havingtolistentoaspeakerNewVHFandHFradiotelephoneshave
DSCcapability
AllDSC-equippedradios,andmostGPSreceivers,haveadata
interfaceconnectorTheinterfaceallowsmostmodelsofGPStobe
successfullyinterconnectedtoDSC-capableradios,regardlessof
manufactureTheCoastGuardrecommendsthatyouinterconnect
yourGPSandDSC-equippedradioDoingsomaysaveyourlifeinan
emergencysituation
UsersofaVHF-FMmarineradioequippedwithDigitalSelectiveCalling
willalsoneedtoobtainaMaritimeMobileServiceIdentity(MMSI)
numberTheseareavailablefromBoatUS,SeaTow,theFCCandthe
UnitedStatesPowerSquadrons®MoreinformationonDigitalSelec-
tive
Callingisavailableonlineatwwwnavcenuscggov/MARCOMMS/
gmdss/dschtm
WhenproperlyregisteredwithanMMSInumberandinterfacedwith
GPS,theDSCradiosignaltransmitsvitalvesselinformationinan
emergencyWithonepushofabutton,yourDSCradiosendsanauto-
mateddigitaldistressalertcontainingyourMMSInumber,position,and
thenatureofthedistress(ifentered)tootherDSC-equippedvessels
andrescuefacilities

Rescue21istheadvancedcommand,control,andcommunications
systemcreatedtoimprovesearchandrescuewithstrongerVHF-FM
marineradiosignals,direction-findingcapabilities,trackingofships
andaircraft,andbettercommunicationswithstateandlocalfirst-
respondersThesystemiscurrentlybeinginstalledinstagesacross
thecontiguous48states,Alaska,Hawaii,Guam,PuertoRico,andthe
GreatLakesWhenfullydeployed,itwillformthebackboneoftheUS
CoastGuard’sshort-rangecommunicationssystem
Withincreasedcommunicationscoverage,advanceddirectionfinding
capabilities,andDigitalSelectiveCalling,Rescue21helpstakethe
“search”outofsearchandrescue
Capabilities:
• Incorporatesdirection-findingequipmenttoimprovelocatingves-
selsindistress
• Enhancestheclarityofdistresscalls
• Upgradesplaybackandrecordingfeatureofdistresscalls
• Allowssimultaneouschannelmonitoring
• Providesfullcoverageoutto20nauticalmilesfromthecoastline
•
Reducescoveragegapsforcoastalcommunicationsandalong
navigableriversandwaterways
• SupportsDigitalSelectiveCalling
• Portabletowersforrestorationofcommunicationsduringemer-
genciesornaturaldisasters
• Improvesinteroperabilityamongfederal,state,andlocalagencies
TotakefulladvantageofRescue21,boatoperatorsshouldupgradeto
aDSC-capableVHF-FMmarineradio,obtainaMaritimeMobileService
Identity(MMSI)number,enterthenumberintotheirradio,andconnect
theradiotoaGPSreceiver

IfyourvesselisequippedwithaDSC-capableradio,andyouhave
obtainedandregisteredanMMSInumberanditisproperlyconnected
toaGPSreceiver,youneedonlypresstheredDSCEmergency
CallButtonfor5secondsYourvesselinformationandpositionwill
automaticallybetransmitted,includingthenatureofthedistress(if
entered),andaDSCreplyshouldbereceivedUponreceiptofthis
acknowledgement,yourradioshouldautomaticallyshifttoChannel16
tocontinuevoicecommunicationswithrescueassetsIfnoreplyis
received,switchtheChannel16andusetheproceduresbelow

Channel16istheprimaryradiochannelforshipsindistressTomake
adistresscallonmarineVHF-FMChannel16:
1Makesureradioison
2SelectChannel16forstandardmarineVHF
3Press/holdthetransmitbutton
4Clearlysay:MAYDAY,MAYDAY,MAYDAY