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Discussion Starter · #1 ·
Hello,

I am installing a new VHF radio on my boat. It will be connected to GPS and will have an MMSI number installed. I also bought a new hand held VHF (Standard Horizon HX851) with built in GPS and DSC functions. I need to get an MMSI number for the hand held.

My question is should I use the same MMSI as the VHF on the big boat or get a separate MMSI number?

The Hand Held will be used primarily on the boat but I also will use it on my kayak and dinghy. Sometimes I take the kayak on the big boat, sail somewhere, anchor, and use the kayak to explore. My kids may take the dinghy exploring as well.

The Hand Held with GPS will be useful when kayaking or dinghy-ing to keep in touch with the big boat. I just realized that one DSC function is position request / send. I can send / request the position of the hand held and the location will be displayed on the plotter of the big boat. But, to do that, I would need a separate MMSI number.

Comments?
 

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Hello,

I am installing a new VHF radio on my boat. It will be connected to GPS and will have an MMSI number installed. I also bought a new hand held VHF (Standard Horizon HX851) with built in GPS and DSC functions. I need to get an MMSI number for the hand held.

My question is should I use the same MMSI as the VHF on the big boat or get a separate MMSI number?

The Hand Held will be used primarily on the boat but I also will use it on my kayak and dinghy. Sometimes I take the kayak on the big boat, sail somewhere, anchor, and use the kayak to explore. My kids may take the dinghy exploring as well.

The Hand Held with GPS will be useful when kayaking or dinghy-ing to keep in touch with the big boat. I just realized that one DSC function is position request / send. I can send / request the position of the hand held and the location will be displayed on the plotter of the big boat. But, to do that, I would need a separate MMSI number.

Comments?
We have a similar setup, I just bought the HX851 too.

After asking the same question I opted to use the same MMSI number. Others had tested it and told me they had tried calling the mother ship that way and it worked OK.

I bought this radio specifically to go in the ditch bag, so having the mother ship info come up isn't a bad thing in my book.

The number if DSC functions I will use in daily life is probably next to zero.
 

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You can do it either way, but need to consider how you use your radio. I bought Uniden's DSC handheld (for less than half the HX851), and registered it separately because I will use it on a dinghy and may use it on a charter. I'll update the MMSI website with my charter boat info before heading out.

If you use the same MMSI, I'd strongly recommend turning OFF the handheld's auto-acknolwedge feature, otherwise DSC position requests from other radios will get duplicate responses (which might interfere with each other). And if someone is out on a dinghy with the handheld, the disagreement between those duplicate auto ack's will create huge confusion. Note that if you register the handheld separately, you can ping the handheld while the kids have it in the dinghy to determine where they are located. This feature will not work if both radios have the same MMSI.

...The number if DSC functions I will use in daily life is probably next to zero.
You may not use them, but others may use them to ping your location. So you need to turn off auto-ack on at least one of your radios.

BoatUS FAQs:
I have more than one radio on my boat. Can they use the same MMSI number?

Yes. If you have 2 fixed mount radios on the same boat you may input the same MMSI number in both radios

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I have a handheld radio on board my boat. Should it have it's own MMSI number?

If you plan to use the handheld on other boats, you might want a separate MMSI number so that you can update the registration according to which boat it is currently on. If you plan to use it only on one boat, you can use the same MMSI number as the fixed radio.

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I have a VHF Handheld with DSC capability. Can I register it for an MMSI through your
website?

If the handheld is for Marine use, yes; however you would need to keep the registration updated according to the specifics of which boat it is being used on. Reason being, the USCG could be misled in a distress situation thinking a distress came from a boat other than the one actually involved and could end up dispatching the wrong type of rescue unit or calling the wrong emergency contact in any particular situation. Also, it would be inappropriate to register handheld VHF if the intention is for over land use such as hiking. The Coast Guard will not be the appropriate response for this type of distress. Use of Marine VHF Radios on land is prohibited.
 

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Guess it depends on how you are going to use the radio. Most people I know use the MMSI assigned to the VHF on the boat. Gordon West offered another idea for those who were not going every be required to have an FCC-issued MMSI.

Gordon West's suggestion was to have a unique number issued by Boat/US, and reference this number as a portable back to the main boat. That way everyone would know which radio was being used. Keep in mind this is only an option for US boats that don't require a radio license.

Fine Tuner | Sail Magazine
 

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As TakeFive noted. And also, since the handheld will be "wandering" and used away from the boat, it really should have a separate "Portable" ship's station license assigned to it. That makes it legal to be used on other vessels, separately from the vessel attached to the other license. Of course that would mean a separate license fee, which is a downside. (Thieving [email protected] at the FCC keep ignoring the fact that their fees are supposed to be based on their costs, not on "what the market of rich boaters can bear".
 

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We use the same MMSI number, as the handheld is in the ditchbag. If it is turned on, the mother ship must not be transmitting. :eek:

Perhaps your kids don't have cell phones, but that is clearly how we stay in touch when parties separate near shore. If you're in LIS, I wouldn't think coverage was an issue. The problem with using VHF is both radios must actually be on and turned up high enough to recognize the hail. That means you will listen to every other hail as well. ....."yo, anyone out deya gimme a radio check?...." I get enough of that when underway.
 

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...The problem with using VHF is both radios must actually be on and turned up high enough to recognize the hail. That means you will listen to every other hail as well. ....."yo, anyone out deya gimme a radio check?...."
I don't think this is totally correct. If you have two DSC radios properly configured with GPS (and turned on), and both have their own MMSI (available for free from BoatUS for domestic use only), then you can activate auto position reply on the handheld (or fixed VHF), and it will reply automatically to any position requests that it receives. There is no need to turn up the volume and/or listen to radio chatter - it's all done automatically as part of the DSC protocol, with digital requests and responses that show up on the screen of the hailing radio. No voice communications are needed for this feature. In many ways, it's more safe and foolproof than having your kid pull his cell phone out while he's motoring across the water (if he would even hear it over the motor). There are similar tracking features available on smartphones, but OP was asking about his new handheld.
 

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Keep in mind a BoatUS MMSI is only good for use in US waters. Your boat may never leave the US, but is that may not hold true for the handheld.
 

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takefive, you are essentially right about the DSC feature. I was thinking they wanted to talk, not track. However, you can hail with DSC as well. Still, I think cell phones are much easier and neither a cell nor a vhf should be used by the kids while motoring along on the dinghy.

Ironically, I'm thinking of my kids in this context now. If it just wanted to ask something simple, like "when will you be back" or confirm they are alive with an innocuous "having fun?", a text message is the only thing they would reply to. :)

p.s. There is a reason the USCG almost always asks if the hailing vessel has a cell phone aboard. :)
 

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Discussion Starter · #10 ·
Hi Guys,

Thanks for the responses. As I expected, it's not so clear cut.

I am going to get a separate MMSI number for the HH. This way I can use it on a number of different boats and I will TRY to update the records at the BoatUS site (have to remember to do that when I'm going out on a different vessel). This could also come in handy when I race on Other People's Boats (OPB).

My kids do have phones. However, I have found that kayaks and cell phones don't really mix (don't ask me how I know). The HH is waterproof so it will survive a dunking in the salt water. One of the times we were kayaking, my wife and I were on the kayak and my kids were on the boat. We kept in touch via VHF and that worked well. If they can see our location that might cut down on the 'when will you be back' stuff.

I'm really hoping that the location request DSC stuff really works. That would be pretty cool to use.

Thanks again,
Barry
 

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....However, I have found that kayaks and cell phones don't really mix (don't ask me how I know).....
Waterproof cell covers are about $10. Good to have on the boat too. Some models float.
 

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I am installing a new VHF radio on my boat. It will be connected to GPS and will have an MMSI number installed. I also bought a new hand held VHF (Standard Horizon HX851) with built in GPS and DSC functions. I need to get an MMSI number for the hand held.
You can use the boat MMSI or get a separate one.

I sit on the USCG GMDSS Task Force.

Unfortunately, not all radio manufacturers interpret the ITU and USCG specifications the same way. You are supposed to be able to call another radio with the same MMSI and have it respond properly. Unfortunately not all do so. The combination of my Icom VHF aboard and Standard Horizon handheld VHF don't play well together.

My solution is an FCC ship station license for Auspicious with a MMSI programmed into the fixed VHF and SSB radios. I have a Boat/US MMSI (free) programmed into the handheld.

Implications:

When one of us is off the boat in the dinghy we can keep the volume turned down on the radios and still beep each other with DSC.

If we are outside the US and use DSC for distress on the heldhead the Boat/US MMSI will not connect to boat information. Location will be passed. Not desirable, but not the end of the world either.

And also, since the handheld will be "wandering" and used away from the boat, it really should have a separate "Portable" ship's station license assigned to it. That makes it legal to be used on other vessels, separately from the vessel attached to the other license. Of course that would mean a separate license fee, which is a downside.
I don't agree. Portable stations are covered by the main ship stations license. In principle that means you shouldn't use DSC from a handheld with a Boat/US MMSI outside the US, but voice is covered as a portable associated with the main license.
 

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I sit on the USCG GMDSS Task Force.
Have you read this document? http://www.itu.int/dms_pubrec/itu-r/rec/m/R-REC-M.585-6-201201-I!!PDF-E.pdf

Assignment of identities for handheld VHF transceivers with digital selective
calling and global navigation satellite system


1. 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.

2. The handheld VHF transceiver with DSC and GNSS should be used exclusively in the maritime mobile service.

3. 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.

4. The procedure and criteria for assignment and registration of these identities should be left
to the administration concerned.

5. Some minimum of procedures for registration of this identity should be observed:
a) Some minimum of procedures for registration of this identity should be observed:
b) the reuse of this identity should follow the guidance of Annex 3 of this Recommendation.
6. 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.
Norway have only one source for MMSI numbers, this recommendation from ITU was implemented from January 1 2013.

All the "standard/old" MMSI numbers here end with the digit 0, so the procedure is to add 8 to the start of the "mother ship" MMSI and remove the trailing 0.
 

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Auspicious, I don't disagree with you. I'm only suggesting that if the primary use of the h/t is going to be as a floater, used primarily away from the vessel that the main licensed was assigned to, that it probably should be licensed separately. Not that it has to be--but that a separate license is preferable if it is primarily used separately, i.e. for deliveries and charters and whatnot.

Of course when they were $75/10 years that wasn't totally unreasonable but at, what is it this week, $225 for the same ten years? The phrase "Frankly, Scarlett, I don't give a damn." comes to mind.
 
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