VHF alarm

[Sivaa]

Receiving false Distress Relay DSC message , from same source or different ? - Sir . If reception is not confirmed either by voice message or by nearby mariner's acceptance for similar reception of message - your receiver is sensitive .

Distress relay if done by fellow mariner ( another vessel which is safe and asks for additional support for the vessel in distress ) , we get voice message - as per procedure . If Relay was done by shore authorities , towards the coordinates- we need to give attention .

One type as Geographic call is available . Whoever is sending this message , their nearby radius mariners only will receive this type of DSC message . Radius is fed in terms of format . SSB will have this function .

If false alert is confirmed , supplier can be contacted along with its alarm history details . Possibly with stand by Unit , you may cross check the validity of DSC message as well . Either warranty based replacement or repair is on the cards .

VHF Ch 16 is mandatory . One should not use more than 30 seconds , in a stretch . After getting a link with another mariner , another channel is mutually selected for further communication .

If we initiate DSC call from our VHF unit ; it will transmit preformatted DSC message for 5 times ie within 90 seconds . Again , it will retransmit DSC message , within 90 seconds .For SSB , in 3 minutes - retransmit will happen .

To cancel out DSC message , DSC menu needs to be opened . We will get cancel DSC message option . This needs to be selected . With this function , retransmission & on-going transmission will get terminated . As well , we convey this calc message in CH 16 .

To cancel DSC message when we receive in our units :-
Sender should assure that they are safe . If they are not able to cancel the message , by acknowledging this message from our units - we can stop retransmission from their unit . Acknowledge function is meant for shore authority ie deciding authority alike RCC , On Scene Coordinator .

When vessel in distress is not in a position to transmit distress alert , fellow mariner will transmit Distress Relay Alert . Shore authority can also transmit Distress Relay alert based on SAT-C distress alerts .

Ch 16 is useful for safe sailing . We need to maintain radio watch on this . One may reduce the volume . DSC reception remains on .

When we receive these alerts , AIS can help to identify the location of sender's MMSI & particulars . If we are nearer , we interact for their assistance - in need . At times , Based on our vessel's capability & vulnerability - we have to raise distress Relay on their behalf with their coordinates and distress details .

In genuine cases , our boat or vessel becomes On-Scene Coordinator either due to nearby distance or due to available capability.

In fact , when distress Relay is received from RCC - we need to send message to RCC by conveying our capabilities. RCC will appoint OSC ( On - Scene Coordinator ) and can details vessels for rescue operation. In distress situations , these are followed .

1. Relay message should reach shore authorities .

2. Due to distress situation , if vessel in distress cannot maintain radio station - Distress Relay message is transmitted by another vessel .

3. When RCC transmits Relay message , verbal or electronic communication is done by stating our position & capabilities .

Certain facts remain same irrespective of geographical region . For references . Regards .

[goboatingnow]

Originally Posted by Sivaa

Receiving false Distress Relay DSC message , from same source or different ? - Sir . If reception is not confirmed either by voice message or by nearby mariner's acceptance for similar reception of message - your receiver is sensitive .

Distress relay if done by fellow mariner ( another vessel which is safe and asks for additional support for the vessel in distress ) , we get voice message - as per procedure . If Relay was done by shore authorities , towards the coordinates- we need to give attention .

One type as Geographic call is available . Whoever is sending this message , their nearby radius mariners only will receive this type of DSC message . Radius is fed in terms of format . SSB will have this function .

If false alert is confirmed , supplier can be contacted along with its alarm history details . Possibly with stand by Unit , you may cross check the validity of DSC message as well . Either warranty based replacement or repair is on the cards .

VHF Ch 16 is mandatory . One should not use more than 30 seconds , in a stretch . After getting a link with another mariner , another channel is mutually selected for further communication .

If we initiate DSC call from our VHF unit ; it will transmit preformatted DSC message for 5 times ie within 90 seconds . Again , it will retransmit DSC message , within 90 seconds .For SSB , in 3 minutes - retransmit will happen .

To cancel out DSC message , DSC menu needs to be opened . We will get cancel DSC message option . This needs to be selected . With this function , retransmission & on-going transmission will get terminated . As well , we convey this calc message in CH 16 .

To cancel DSC message when we receive in our units :-
Sender should assure that they are safe . If they are not able to cancel the message , by acknowledging this message from our units - we can stop retransmission from their unit . Acknowledge function is meant for shore authority ie deciding authority alike RCC , On Scene Coordinator .

When vessel in distress is not in a position to transmit distress alert , fellow mariner will transmit Distress Relay Alert . Shore authority can also transmit Distress Relay alert based on SAT-C distress alerts .

Ch 16 is useful for safe sailing . We need to maintain radio watch on this . One may reduce the volume . DSC reception remains on .

When we receive these alerts , AIS can help to identify the location of sender's MMSI & particulars . If we are nearer , we interact for their assistance - in need . At times , Based on our vessel's capability & vulnerability - we have to raise distress Relay on their behalf with their coordinates and distress details .

In genuine cases , our boat or vessel becomes On-Scene Coordinator either due to nearby distance or due to available capability.

In fact , when distress Relay is received from RCC - we need to send message to RCC by conveying our capabilities. RCC will appoint OSC ( On - Scene Coordinator ) and can details vessels for rescue operation. In distress situations , these are followed .

1. Relay message should reach shore authorities .

2. Due to distress situation , if vessel in distress cannot maintain radio station - Distress Relay message is transmitted by another vessel .

3. When RCC transmits Relay message , verbal or electronic communication is done by stating our position & capabilities .

Certain facts remain same irrespective of geographical region . For references . Regards .

Just a point other then shore station all mayday relays are by voice procedure only , do not use dsc distress relay to relay a mayday relay

[Sivaa]

Distress alerts are to be acknowledged by Shore Station so that Shore Station makes sure to address the grievances .

When vessel is not in a position to raise distress alert or if not acknowledged by store Station due to communicating equipments- nearby mariner can raise DSC distress relay alert .

When coastal stations are with MF and boaters are with VHF capability - this may apply too . Nearby mariners pick up VHF . Shore authorities need to be addressed .

We have options to raise DSC relay alert . In this , repeated monitoring from our side will not be necessary so as to address the situation towards authorities . Procedure will support as well .

For references . Regards .

[goboatingnow]

Originally Posted by Sivaa

Distress alerts are to be acknowledged by Shore Station so that Shore Station makes sure to address the grievances .

When vessel is not in a position to raise distress alert or if not acknowledged by store Station due to communicating equipments- nearby mariner can raise DSC distress relay alert .

When coastal stations are with MF and boaters are with VHF capability - this may apply too . Nearby mariners pick up VHF . Shore authorities need to be addressed .

We have options to raise DSC relay alert . Repeated monitoring from our side will not be necessary so as to address the situation towards authorities . Procedure will support as well .

For references . Regards .

I’m sorry , ITU regulations requires that mayday relay is now relayed by voice procedure only. Do not use dsc distress relay facilities and I believe it will be removed from radio units in the near future.

So if you receive a dsc distress alert , and or a mayday relay ( a voice procedure always follows a dsc call action ) , and you realise the MRCC has not responded ( ie not acknowledging the dsc alerts , or responding by voice ) , then assuming you can reach the shore , you should relay the mayday by voice procedure only. ( MAYDAY RELAY )

The goal of GMDSS , is to ensure a mayday or distress alert reaches a shore station ( MRCC) as the primary basis of GMDSS is the MRCC will marshal the rescue assets, not vessels in the vicinity.

I am a RYA VHF instructor

[Sivaa]

Relay alert can be done by mariners too than on voice communication . GMDSS course has these instructions as well ( including UK approved ) .

Directives if available - please provide the link so as to update me as well . Because , we consciously or unconsciously improve ourselves from what we know - in a daily basis ; which is a purpose of this technical forum too . Memory retention needs those references to retain with us . Sooner or later , we would be sharing our collection in our working atmosphere too .

I have a situation with my career commitments as well . Your assistance will help me to handle the details in standard formats . For your clarification , please .