Handheld DSC Radio in USA: Allowed Use; MMSI Assignment

VHF Marine Band radios, protocol, radio communication theory, practical advice; AIS; DSC; MMSI; EPIRB.
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Handheld DSC Radio in USA: Allowed Use; MMSI Assignment

Postby jimh » Sun Sep 10, 2017 2:12 pm

There are two recent regulatory concerns about use of a handheld DSC radio on a recreational boat in the United States of America:

  • the FCC regulations about use ashore, and
  • the proper maritime mobile service identity (MMSI) for the radio.

This article reviews those two topics.

Use of Handheld Radios On Shore
The FCC recently amended its rules for Part 80 (Maritime Radio Service) to permit limited use of VHF Marine Band handheld radios on shore. Use on shore was granted in a limited fashion for specific purposes over a limited shore area. For details see

FCC Modifies Regulations to Permit Handheld Radios to be Used On Shore

Any handheld radio—not just a DSC handheld—can be used ashore, but only in areas adjacent to the water such as a dock or beach. And it can "only be used to communicate with the ship station with which it is associated." In other words, you cannot sit on your porch at your home on or near the water, operate as a marine shore station, and use a handheld radio (or any other radio) to communicate from shore to any vessel you might want.

MMSI for Handheld Radio
In the numbering for a maritime mobile service identity (MMSI), the governing recommendation is:

This recommendation gives guidance on many instances of MMSI assignments. It recommends:

that ships ...equipped with...DSC...should be assigned maritime mobile service identities in accordance with the Annex 1 to this Recommendation, as appropriate...

And also recommends (which we will soon see applies specifically for VHF handheld radios) that:

...maritime identities used for other maritime devices for special purposes should be assigned as specified in Annex 2...

In Annex 1 we find the familiar MMSI numbering scheme for ships.

In Annex 2 we find the following recommendation for assignment of MMSI number to handheld radios:

  • A handheld VHF transceiver with DSC and GNSS may require a unique identification showing that this device has restricted battery capacity and restricted coverage area. This may give additional information in an emergency case.
  • The handheld VHF transceiver with DSC and GNSS should be used exclusively in the maritime mobile service.
  • Handheld VHF transceiver with DSC and GNSS participating in the maritime mobile service should be assigned a unique 9-digit number in the format 8MIDXXXXX where digits 2, 3 and 4 represents the MID and X is any figure from 0 to 9. The MID represents the administration assigning the identity to the handheld transceiver.
  • The procedure and criteria for assignment and registration of these identities should be left to the administration concerned.
  • Some minimum of procedures for registration of this identity should be observed:
    1. all identities in this category should be registered by the national authority concerned, and the local RCC or MRCC should be able to access the data on a 24 hour-per-day, 7 days-per-week basis. In systems that have automatic distress priority, this information should be automatically forwarded to an RCC;
    2. the reuse of this identity should follow the guidance of Annex 3 of this Recommendation.
  • The administration may use the 5th digit to differentiate between certain specific uses/users of the maritime identity. However, this method is optional and for national use only.

Note that in this recommendation, there is no mention of a concept of a handheld radio as being subject to some determination of being in one of two categories: primarily associated with one vessel; or not. The recommendation seems to be intended to apply to all handheld radios with DSC and GNSS. This first comment in the recommendation is significant: the MMSI of the radio could identify the source of a distress alert call as coming from a handheld DSC radio with limited battery capacity; this information COULD be useful to rescuers.

The notion that the distinction between handheld radios being primarily associated with one vessel or handheld radios having no primary vessel association seems to have been added by the U.S. Coast Guard or the F.C.C. in their recommendations.

We now look to those sources for further advice about MMSI assignment to handheld DSC radios.

The best source of authority for assignment of MMSI to handheld radios in the USA is probably found at

USCG NavCen Website for MMSI

See the section under the heading "Obtaining MMSIs for DSC-equipped VHF Handhelds", which says:

A handheld VHF transceiver with DSC and an integral global navigation satellite system (e.g. GPS) not intended for dedicated use on a particular ship (e.g. a diver’s radio) should be assigned a unique 9-digit number in the format [8MIDXXXXX]. While currently means do not exist within the U.S. to assign such identities, the Coast Guard has been in discussions with the Federal communications Commission and others on implementing them.

In the interim, VHF handhelds used in the United States should use the MMSI assigned to the ship to which the handheld is primarily associated, even if another radio on that ship uses the same MMSI. Non-commercial users of VHF handhelds not primarily associated with any single ship may use an MMSI provided by an organization such as BOAT US, SEA TOW and U.S. Power Squadron....

Please note the problem in the USA, as "currently means do not exist within the U.S." to comply with the recommended numbering scheme for MMSI assignments to handheld radios. Where does that leave a boater with a handheld radio?

The answer—provided by the Coast Guard—seems to be, for the moment, for a handheld radio NOT PRIMARILY associated with a single vessel which has its own GNSS receiver, to get an MMSI from a licensed-by-rule agency (BoatUS and others) for the handheld as if it were its own vessel, that is, an MMSI in the format MIDXXXXXX.

If the handheld IS PRIMARILY ASSOCIATED with a single vessel, then use the MMSI of the primary vessel for the handheld.

A good summary of MMSI number schemes is found at

MMSI Number Scheme

Now we come to a question of defining what constitutes a handheld radio that is "not primarily associated with a single ship." I don't know that there is an explicit definition of that category. However, it seems reasonable that if you own one vessel and own one handheld radio, that hand held radio is PRIMARILY associated with a single ship. The notion that at some time and some place you might carry that handheld radio with you and go aboard another vessel does not seem like it nullifies the primary use of the handheld with your own vessel.

I also seems reasonable that if you are someone who does not own any vessel, but you do own a DSC handheld radio and use it when you are aboard vessels owned by others, then your radio cannot be primarily associated with one vessel. For example, a diver might own a radio and not a boat.

Now we consider someone who owns more than one vessel. Maybe you have two boats and carry the handheld between them. Perhaps this also constitutes a situation in which the handheld radio is not primarily associated with a single vessel, although if you use the radio most of the time with just one of the boats you own, perhaps that constitutes a primary use with a single vessel.

But, again, at this time much of this MMSI deliberation is an academic exercise because there are at present no means for anyone in the USA to obtain an MMSI for a handheld radio in the recommended format, and the advice given is just to get an MMSI as if the handheld were incongruously a vessel onto itself. But for a boater who owns one boat and one handheld radio, the best advice seems to be that the handheld radio should use the same MMSI as his boat.

Posts: 11869
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula

Re: Handheld DSC Radio in USA: Allowed Use; MMSI Assignment

Postby jimh » Wed Apr 24, 2024 12:59 pm

UPDATE: the FCC is now issuing maritime mobile service identities (MMSI) for handheld radios. See


In addition, SHINE MICRO is now authorized for issuing maritime mobile service identities (MMSI) for handheld radios. See