Group MMSI for DCS calling while cruising

This summer, we are part of a 9 boat flotilla venturing from the upper reaches of the Potomac River, out to the southern portion of the Chesapeake Bay, with our furthest destination being Portsmouth, VA. About a 400 mile round trip with boat ranging is size from 33' to 54' with cruising speeds and ranges all over the map.

I would like to set up a Group MMSI for the flotilla. If most boaters are like me, I got my MMSI number throught BoatUS because it was free and I do not anticipate operating my boat in waters outside of the US. If I had received the MMSI from the FCC, it would have cost me about $120, or so I've read.

The instructions that I can find from the USCG regarding establishing a Group MMSI are predicated on the assumption that you obtained your MMSI from the FCC. What makes this significant is that all FCC obtained MMSI's end in the number zero (0). The recommendation is just to mover the zero to the front of the 9-digit string and that becomes the Group MMSI. See attached: https://www.navcen.uscg.gov/?pageName=mtMmsi

For those of us that obtained our MMSI from BoatUS or the like (not the FCC), our numbers, at least mine, do not end in a zero. My first three digits, also called the MID, is a country identifier, and for the US that number is 338. So drum roll please........if my MMSI is 338XXXXXX, can I input a group MMSI as 0338XXXXX?

Jaybeaux

Wow Jaybeaux - 9 out of 9 boats are equipped with DSC/MMSI!?!?

I'm seriously impressed. I've been trying to increase compliance in my boating circle, but my success rate is dismal. So bad in fact, that I wasn't aware how complex group calling is. I thought it was just a matter of grouping the MMSI numbers together. Learning something everyday!

Since my own friends have been dragging their feet getting setup, I decided to start a thread in our marina's FB group. It couldn't have gone worse - only my friends who haven't completed their setup even hit "like". One of the responses from a random dockholder was:

"My daughter the Waitress works at the OLD STEAK House i call IT.....LOL"

???? I have so far resisted the urge to reply: "perhaps you're too stupid or drunk to share a lake with other humans..."

The MMSI's we have are also from BoatUS, so I'll be watching this thread to see how it shakes out.

Below is some interesting info:

https://en.wikipedia.org/wiki/Maritime_Mobile_Service_Identity

Group ship station call identities
Group ship station call identities for calling simultaneously more than one ship are formed as follows:
0MIDxxxxx
where the first figure is zero, and X is any figure from 0 to 9. The particular MID represents only the country assigning the group ship station call identity and so does not prevent group calls to fleets containing more than one ship nationality.

Coast station identities
Coast station identities are formed as follows:
00MIDxxxx
where the first two figures are zeros, and X is any figure from 0 to 9. The MID reflects the country in which the coast station or coast earth station is located.

Group coast station call identities
Group coast station call identities for calling simultaneously more than one coast station have the same format as individual coast station IDs: two leading zeros, the MID, and the four digits.[6] They are formed as a subset of coast station identities, as follows:

00MID0000 for any coast station using the MID
009990000 for any VHF coast station (regardless of MID)
US Coast Guard stations use a non-standard MMSI: 003669999 - any US Coast Guard Base station Note that administrations in other countries may use different formats.

Reference: ITU-R Recommendations M.585-7

Stee....very nice. So if I am reading this correctly, I can create a group MMIS for our flotilla in the format 0338XXXXX where essentially I get to pick all of the X's? From my link above.....

MMSI Format
Maritime Identification Digits (MID)
MIDs are three digit identifiers ranging from 201 to 775 denoting the administration (country) or geographical area of the administration responsible for the ship station so identified. See the ITU Table of Maritime Identification Digits.

Ships
All ship MMSIs use the format M1 I2D3X4X5X6X7X8X9 where in the first three digits represent the Maritime Identification Digits (MID) and X is any figure from 0 to 9. (Hint: Ships transmitting with an MMSI not starting with the digits 201-775 are likely doing so improperly, and may be subject to FCC or USCG enforcement action)
Groups of Ships (DSC only)
Group ship station call identities for calling simultaneously more than one ship use the format 01M2I3D4X5X6X7X8X9, where the first figure is zero and X is any figure from 0 to 9. The MID represents only the territory or geographical area of the administration assigning the group ship station call identity and does not prevent group calls to fleets containing more than one ship nationality.

No process currently exists to assign non-federal group ship station identities. However, users having an MMSI assigned by FCC license, all of which have a trailing zero, may create a group identity by inserting a zero before the identity and removing the trailing zero (e.g. a user having an MMSI of 366123450 is allowed to use the group identity 036612345).

****The italicized portion is where I get confused. A BoatUS MMSI number is not the same as an FCC MMSI number.*****

The U.S. Coast Guard group ship station call identity is 036699999.

Per a recommendation from Jim at BOE Marine, I downloaded the manual for the Standard Horizon GX-2200 as it is AIS equipped. I found this.....(sorry, I couldn't cut and paste. I don't know why)

Basically, the Group MMSI number is of the format 0MIDXXXXX, where the leading zero denotes a group, the MID is the country code, 338 for Lower 48 US; and the XXXXX are five numbers that are decided upon by the persons in the group. All radios in the group must have/use this group MMSI. There is a chance that another group could have the same Group MMSI number. If that is the case, just change a digit.

Hope this helps.

Jaybeaux

Jaybeaux said:

Per a recommendation from Jim at BOE Marine, I downloaded the manual for the Standard Horizon GX-2200 as it is AIS equipped. I found this.....(sorry, I couldn't cut and paste. I don't know why)

Basically, the Group MMSI number is of the format 0MIDXXXXX, where the leading zero denotes a group, the MID is the country code, 338 for Lower 48 US; and the XXXXX are five numbers that are decided upon by the persons in the group. All radios in the group must have/use this group MMSI. There is a chance that another group could have the same Group MMSI number. If that is the case, just change a digit.

Hope this helps.

Jaybeaux

Click to expand...

So what if a boat has a different MID such as 366,367,368, or 369 which are also US codes?

gmacd81, see underlined portion below.

Edit: I originally read your post to mean foreign or non-US vessel. My mistake. While those MIDs you reference are reserved for the US, I am not sure what they are for. Due to the fact that you can include an international boat in the MMSI Group that you create tells me that all members of the group do not have to have the same MID.

https://www.navcen.uscg.gov/?pageName=mtMmsi

Groups of Ships (DSC only)
Group ship station call identities for calling simultaneously more than one ship use the format 01M2I3D4X5X6X7X8X9, where the first figure is zero and X is any figure from 0 to 9. The MID represents only the territory or geographical area of the administration assigning the group ship station call identity and does not prevent group calls to fleets containing more than one ship nationality.

No process currently exists to assign non-federal group ship station identities. However, users having an MMSI assigned by FCC license, all of which have a trailing zero, may create a group identity by inserting a zero before the identity and removing the trailing zero (e.g. a user having an MMSI of 366123450 is allowed to use the group identity 036612345).

The U.S. Coast Guard group ship station call identity is 036699999.