DSC advantages, details + AIS

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Oct 9, 2008
1,733
Bristol 29.9 Dana Point
Howdy,

Have just installed the Standard Horizon GX2150.


Question: If you have registered your MMSI #, a DSC call will include transmitting your MMSI to the recipient. However, if it is only a standard VHF transmission from a registered DSC radio, does it still transmit your MMSI #?


Next, the DSC Distress function with GPS interface is fabulous for safety, especially considering the confusion and stress that can occur during an emergency. Next question: What happens if you use the Distress button and you have not registered your MMSI #? Can it still transmit your position and other GPS data?


Last: Other than the aforementioned safety usage, I view the DSC function as somewhat useless. I mean, who are you going to call? How do you get their MMSI#? Of course, there are people who like the gadgetry (including me) and invent neat things to do to play with their sailing mates, but in the real world is it genuinely usefull? I mean, If I could choose the option of transmitting my position, SOG, COG, boat name, etc, to other DSC radios automatically, without the need for their MMSI#, then that would be a fabulous safety usage during limited visibility situations, especially since so many boats don't have radar, yet DSC radios are plentyfull. When connected to a chart plotter, or even a rudamntary dot matrix on the radio itself, you could then see drastically more boats on the water than with only AIS.


Speaking of AIS, my radio has the rcvr built in, and I can see AIS boats on the chartplotter. If I were worried about proximity, I could then DSC call an AIS ship (as the ship's MMSI # is transmitted via AIS), which would then ring an alarm on their bridge, and instantly give them my position, SOG, COG, boat name, etc. It simultaneously gives me the ability to avoid them, and allow them to know I'm there, even if their radar can't see my fiberglass boat or that might be below their radar. I only wish I could do this type of transmission without the need for the AIS data, as mentioned previously.
 
Nov 8, 2010
11,385
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
Answers in-line.

Howdy,

Have just installed the Standard Horizon GX2150.


Question: If you have registered your MMSI #, a DSC call will include transmitting your MMSI to the recipient. However, if it is only a standard VHF transmission from a registered DSC radio, does it still transmit your MMSI #?

Like on Ch#16? NO


Next, the DSC Distress function with GPS interface is fabulous for safety, especially considering the confusion and stress that can occur during an emergency. Next question: What happens if you use the Distress button and you have not registered your MMSI #? Can it still transmit your position and other GPS data?

Until you enter an MMSI into the radio, you cannot use the DSC distress button (it does not let you). You COULD enter a made up number. But that would NOT be a good idea.


Last: Other than the aforementioned safety usage, I view the DSC function as somewhat useless. I mean, who are you going to call? How do you get their MMSI#? Of course, there are people who like the gadgetry (including me) and invent neat things to do to play with their sailing mates, but in the real world is it genuinely usefull? I mean, If I could choose the option of transmitting my position, SOG, COG, boat name, etc, to other DSC radios automatically, without the need for their MMSI#, then that would be a fabulous safety usage during limited visibility situations, especially since so many boats don't have radar, yet DSC radios are plentyfull. When connected to a chart plotter, or even a rudamntary dot matrix on the radio itself, you could then see drastically more boats on the water than with only AIS.

If you have your friends MMSI numbers, you can call them at 1AM for more rum without waking the entire anchorage! ;^)

The direct MMSI call was originally intended for class A boats that broadcast them MMSI over AIS. You are correct its more limited if you do not broadcast yours. Class B AIS devices are receive-only
 
Oct 2, 2006
1,517
Jboat J24 commack
My standard horizon HX851 handheld6W Floating Hand held VHF with internal GPS, glow-in-the dark gasket, waypoint navigation and a compass display.

Is a great DSC safety device as it floats and has a great belt clip so it goes were i go good or bad and its got the fastest freaking GPS i have ever seen and gets a full single in my basement

In my area of Long Island Sound the towers are high and the handheld is always in range

All i have to do is be able enough to hit the red button and they know were i am

If i have on my hands i can send the exact nature of my emergency to allow a better response for
fire/mob/long preprogrammed list :)

I would hope the fixed unit is a least that good ?

 
Jan 28, 2012
101
2006 Hunter 33 Santa Barbara
My standard horizon HX851 handheld6W Floating Hand held VHF with internal GPS, glow-in-the dark gasket, waypoint navigation and a compass display.

Is a great DSC safety device as it floats and has a great belt clip so it goes were i go good or bad and its got the fastest freaking GPS i have ever seen and gets a full single in my basement

I would hope the fixed unit is a least that good ?

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I've got an HX851 too, but I'm not sure it works properly. It's got the ability to send a test message to another VHF if you know that VHF's MMSI. When I try to send a test msg to my fixed mount radio, it doesn't work. The handheld shows a msg saying "waiting for ack" (or something like it), and the fixed mount doesn't do anything if tuned to ch16. But if tuned to ch 70 (the DSC channel) it beeps and displays "DSC Error" (so at least something is getting through!)

After I did the test, though, I thought through that I was in the boat's cabin at the time - almost directly under the fixed mount's antenna. Perhaps that was the problem, and I'll try again positioned some way away from the boat.

But to answer Skipper's original question, when you press the distress button on a DSC radio, a msg should be received by ALL other DSCs in range giving your GPS location, nature of distress, your MMSI, etc. The main benefit of this is that the Coast Guard should get it (if in range) and they can get more info about you and your boat from your MMSI. Yes, there are DSC functions where you can address only specific other MMSIs, but not in the case of a distress msg.

BTW in the case of EPIRBs, they also use a unique identifier (not MMSI - a different one), and the Coast guard get the tel # of a contact from the data base of unique identifiers when the EPIRB goes off. They then call that contact to see if you really are likely to be on the boat at the approx location. Then if so - they dispatch help, and otherwise not. Seems sensible ... except I've often wondered what they do if there in no answer on the contact's line. I'd hate to wait a weekend for CG help if my contact has gone away for the weekend! However, in the case of DSC, I don't think they do this contact thing.
 
Jan 14, 2011
243
tanzer tanzer 28 bathurst nb
it is very usefull

I have my mmsi number and a few friend to. get it while it is still free. You will be able to request your friend position, call them privatly and have a private conversation on your vhf. You just have to know their mmsi and input it in your vhf.

And you will have the added security of having a button for emergency that will give search and rescue the type of boat and the color and the usual number of people aboard.
 
Jan 28, 2012
101
2006 Hunter 33 Santa Barbara
I have my mmsi number and a few friend to. get it while it is still free. You will be able to request your friend position, .
Yes, you can get an MMSI for free from USBoat or US Power Squadron for free, but be aware that the MMSI you get from them can only (legally) be used in US waters. If you're contemplating going abroad - even to Canada, Mexico or Bahamas, you need a ship's station licence from the FCC that'll cost you (about $140 for 10 yrs if I remember).

And many DSC radios are limited in the number of times you can load an MMSI. My 6 yr old fixed radio allows 2 changes to MMSI only. My (much newer) DSC hand-held allows NO changes to MMSI once it is entered.
 
Feb 26, 2004
22,013
Catalina 34 224 Maple Bay, BC, Canada
If you have an MMSI # you most likely got it from BoatUS.

The BoatUS website has a lot of information about how it works.

If you don't have it hooked up to a GPS it cannot send any position information.
 
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
I have an Icom M402 DSC VHF. It has an RCA phono plug on the back to accept a GPS NMEA input. Icom mention in the manual they do not make or supply a GPS to plug into it. Does anyone make one ?

My last boat had a Raymarine VHF and I connected it to my Garmin plotter. It all worked well and I could see another boat on the plotter.

I think on the boat we now have I would sooner have it connected to its own GPS rather than connect it to the Raymarine C120W on the helm.

I am wondering if someone makes a little puck type GPS to do this job ?

Bob
 
Feb 26, 2004
22,013
Catalina 34 224 Maple Bay, BC, Canada
Bob, the little puck type GPS units are all USB, not RCA, as far as I know. Google BU-535 or 353.
 
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
thanks Stu,

it seems odd that no one makes 12 volt GPS puck with an RS232 output,

Google does not show any kind of simple turnkey solution, most want 5V to run so that means making a 5V power supply to run off of 12V...........not a big deal but I have enough to do without getting into interfacing one of these to the VHF........

still surprised that Icom did not offer one for the radios.........

I'll just put this off until later, maybe put something together to do the job next summer and plug it in next winter when we put the boat back in the water...

Bob
 
May 27, 2004
1,707
Hunter 30_74-83 Ponce Inlet FL
I've tried to hook up and make work my Garmin and Icom units for years with no luck.
Finally I bought a new Standard Horizon VHF from West Marine last week when I was told that this new fixed mount model, which connects to my masthead antenna, had a built-in GPS.
I haven't installed it yet, but I'll report model number and status/workings/performance next week.
 
Jun 6, 2006
6,991
currently boatless wishing Harrington Harbor North, MD
Don't the newer VHF radios have a gps inside for just that purpose?
 

Erieau

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Apr 3, 2009
209
Oday 25 Erieau
How to find out MMSIs

The website for Radio Spectrum Canada includes a searchable database of every registered Canadian MMSI. Type in the boat names of your pals, up will pop their MMSIs.
Maybe BoatUS has a similar feature?
 
May 7, 2012
985
Hunter e33 Maple Bay, BC
thanks a lot, I just looked at the Garmin site and this looks perfect,

https://buy.garmin.com/shop/shop.do?cID=170&pID=8630

runs on 12 v and outputs RS232 !

looks like the one to use, Bob
Bob, I used the 17xHVS on my last boat and it just did its job with no hiccup. I think you may have trouble locating either Garmin GPS 17HVS or 17xHVS as they have both been discontinued. You may try this site:

http://www.amazon.ca/NEW-GPS-17x-An...MOZ0/ref=sr_1_4?ie=UTF8&qid=1360175125&sr=8-4

shipping to the states, although not free, is reasonable.
 
May 16, 2007
1,509
Boatless ! 26 Ottawa, Ontario
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