MMSI number, call signs???

[UncleWillie]

Re: MMSI number, call signs???

I have to question the need of a call sign seeing that you can contact the party via their MMSI number.

Let's take another hypothetical situation;

You are out fishing with the grandkids.
One of them gets bored and decides to see what that fancy red button does.
He lifts the cover and presses it when you are not looking.

Thirty seconds later the VHF radio comes alive with the call...

"This is the US Coast Guard calling the the Emergency Vessel 321654987, Over"
OR
"This is the US Coast Guard calling the the Emergency Vessel BLUE CRAB", Over"

Do you immediately recognize your MMSI number when you hear it out of the blue? ("Hey, That's me!")
Which call is going to get your attention and allow you to respond and call off the search before it even gets started?

The call sign is all about communications, and making it easy, clear, and unmistakable.

 

[dingbat]

Re: MMSI number, call signs???

Let's take another hypothetical situation;

You are out fishing with the grandkids.
One of them gets bored and decides to see what that fancy red button does.
He lifts the cover and presses it when you are not looking.

Thirty seconds later the VHF radio comes alive with the call...

"This is the US Coast Guard calling the the Emergency Vessel 321654987, Over"
OR
"This is the US Coast Guard calling the the Emergency Vessel BLUE CRAB", Over"

Do you immediately recognize your MMSI number when you hear it out of the blue? ("Hey, That's me!")
Which call is going to get your attention and allow you to respond and call off the search before it even gets started?

The call sign is all about communications, and making it easy, clear, and unmistakable.

Hailing is 20th century technology.

Maybe it is just my fancy DSC radio setup, but I have no need to hail anyone over an open frequency. If I want to talk to Joe down Bay, I select his MMSI number from the contact list on my radio and push the button. A digital message is sent to him to let him knows I am trying to get hold of him on Channel X. He acknowledges the message and both radios automatically tune to the designated channel and we pick up the mike and talk.

In the case of a mayday, the position of the boat sending the Mayday is shown on my GPS and the MMSI is displayed on the radio. I contact the person directly using the method above.


I suggest you review the following information on the functionalty of a DSC radio

mms://www.icomamerica.com/DigitalDistressCalls.wmv

mms://www.icomamerica.com/PositionCall.wmv

mms://www.icomamerica.com/GroupCall.wmv

 

[Larry3215]

Re: MMSI number, call signs???

Not everyone has 21 century radios linked to their 21 century GPS units. On top of that, there are still a great many old farts out there who have no clue how to use MMSI tech beyond pushing the red button and waiting for the old fashioned hail.

 

[UncleWillie]

Re: MMSI number, call signs???

Not everyone has 21 century radios linked to their 21 century GPS units. On top of that, there are still a great many old farts out there who have no clue how to use MMSI tech beyond pushing the red button and waiting for the old fashioned hail.

While I admittedly have no direct experience with sending an actual Emergency/Mayday call over DSC;
I will assume that the CG does not reply over DSC suggesting a voice frequency that they wish to contact you on.

The assumption will be that you are listening for a reply on ch16.
I believe most radios automatically tune to ch16 when the Distress Button is pressed in anticipation of the voice reply.

Which gets us back to the original question; What Voice Call Sign do you want to use? :joyous:

 

[dingbat]

Re: MMSI number, call signs???

While I admittedly have no direct experience with sending an actual Emergency/Mayday call over DSC;
I will assume that the CG does not reply over DSC suggesting a voice frequency that they wish to contact you on.

The assumption will be that you are listening for a reply on ch16.
I believe most radios automatically tune to ch16 when the Distress Button is pressed in anticipation of the voice reply.

Which gets us back to the original question; What Voice Call Sign do you want to use? :joyous:

You know what they say about assuming anything.

A Class A VHF/DSC radio makes use of the "Selective" in DSC by calling other DSC radios by their unique MMSI number. These radios usually provide an electronic notepad that stores names and MMSIs for other boats or shore stations. Another station can be called by selecting the name or number from the stored list, choosing the channel number on which you wish to communicate and pressing a button. A digital call containing the MMSI being called, the MMSI of your radio and the channel number on which you wish to communicate is sent on channel 70. The called radio recognizes its MMSI and alerts its operator to the incoming call by emitting a ringing tone. The radio automatically switches to the communication channel chosen by the caller, allowing voice communication to proceed with no further action required of either party. If your MMSI is stored in the called radio's memory the operator will be informed of your identity as in a land-line caller I.D. system. Depending on the particular capability of the radio, it may also provide call waiting alert and log calls received when the radio was unattended. Overall, a Class A DSC radio performs much like a cellular telephone.



With widespread use, the VHF/DSC system will gradually eliminate the need to monitor the often busy and noisy channel 16 for incoming calls or, as required by regulation, for distress calls. At some time in the future, monitoring of channel 16 will no longer be common practice for most boaters and will no longer be a legal requirement for vessels on the high seas.

Not everyone has 21 century radios linked to their 21 century GPS units. On top of that, there are still a great many old farts out there who have no clue how to use MMSI tech beyond pushing the red button and waiting for the old fashioned hail

Well, we’re now a decade into the 21st century. If you don’t have a unit with DSC capability, you should. If you own this life saving technology and you have not bothered to figure out how to use it, shame on you.

 

[UncleWillie]

Re: MMSI number, call signs???

You know what they say about assuming anything.

Yes! They say 'Every great Idea begins with an assumption.' :facepalm:

So let's assume (again!) your boat doesn't sink immediately after pressing the Distress Button and the Coast Guard replies using the DSC feature and your radio changes channels to 16 or 72 or something else and the radio alerts you to the incoming call.

Eventually you are going to actually be talking to someone and whether you use your FCC Call sign, Your Boat Name, Your Registration number or your MMSI Number, you are going to need a call sign to identify yourself.

You will need a Call Sign for use in everyday transmission in any event. 47 CFR 80.102
Everyone should be aware that for every group of transmissions, you are required to broadcast your Call Sign at the Beginning, the End, and every 15 minutes during the conversation.

You won't need one at the beginning of a DSC initiated exchange, but you will need one at the end.

 

[Pine Sap]

USPS MMSI Registration Form appears to allow only 7 characters. I cannot enter a boat name or registration number with more than 7 characters on their website form.

 

[GA_Boater]

Old thread - 4 years. Please start a new topic if you have questions, otherwise this only a comment to a sleeping thread.

Closed.