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Old 02-03-2011, 08:11   #1
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Resistance to DSC VHF

You may want to look for a read my posts (SV Enough) in the dfib thread.

Why are people so bull headed resistant to getting a free MMSI and programming their DSC that is in their VHF if it was purchased any time after 1996? They seem to think voice is good enough and are so enamored with the sound of their own voice on the radio they would rather scream over the mic in an emergency rather than push DISTRESS and have everything happen automatically. The CG 40 questions checklist for the legal types and keeping comm open and crew engaged could still go on as the important stuff needed to get help moving is done automatically.

About 18 months ago I listened to a 40 question travesty as a local diver died and communication got more and more confused as each side tried to communicate answers to the CG 40 questions AND where they where, where they were headed and status of the patient. This was compounded by the Tampa Bay area having similar or identical local names for completely different places.

About 9 months ago I listened to a repeat travesty on a commercial tug boat as the Engineer died of a heart attack on the galley table as the skipper was on the bridge using the VHF trying to answer medical question on the patient in the galley along with the CG 40 questions. Neither had their DSC capable VHF programmed. The tug had no excuse other than laziness as their vessel was required to have an MMSI and DSC VHF.

In both instances the patient could have gotten to Bayfront Hospital in St. Pete within the golden hour had time not been wasted frantically yacking over the VHF.

My point is that just as an EPIRB response is fully automatic so is a VHF DSC DISTRESS alert only faster. In the tragedy related by another in the dfib discussion, had the skipper who was incapacitated previously connected the VHF to a GPS and programmed the DSC, which was certainly aboard, and if the CG had asked the frantic passenger to push the DISTRESS button that would have been the end of the screaming. All that would remain would be talking to the passenger to keep him calm and talk about the patent and other talk to keep him busy.

Connecting a VHF to a GPS isn't rocket science either, 4 wires for 2 way DSC traffic. Just 2 wires if you don't integrate the VHF DCS back into your navigation system for incoming DSC traffic. You know you have things connected right as the GPS speed, heading and position data it will send can be displayed on the VHF if it is hooked up right.

I just wish folks would talk about this as it is an important part of safe boating in inland and near coastal waters.

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Mark Fay
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Old 02-03-2011, 08:23   #2
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Re: Resistance to DSC VHF

For commercial vessels that's one thing, but you made a statement that you "integrate the DCS into your navigation system". Plenty of pleasure boats (mine included) don't have navigation systems other than charts and a handheld gps as well as other fixing instruments. That in and of itself seems to negate a lot of the benefit of DSC.

In the training videos I've seen, hailing someone via the MMSI takes much longer than simply grabbing 13 and hailing via voice.

DSC wasn't created because people wanted it; it was (as best I understand it) created by authorities to reduce voice traffic.

In regards to the "40 questions", I always thought a big part of that was to allow the USCG to fix your position by all those towers they erected in the last decade or so.

What does a DSC provide that a voice VHF if you know your position doesn't?
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Old 02-03-2011, 08:26   #3
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It's an American Europe is almost totally DSC

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Old 02-03-2011, 08:49   #4
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Re: Resistance to DSC VHF

The problem is that you are constantly being annoyed by false DSC alerts, at least in the busy waters of New England. I have yet to hear a real alert. After awhile you just ignore the alerts. Too much crying wolf. For some reason my ICOM radio deprogrammed itself and lost my MMSI, and the only way to get it reprogrammed is to send it back to the manufacturer, which is a PITA.
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Old 02-03-2011, 08:52   #5
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Re: Resistance to DSC VHF

My main radio is MMSI DSC capable, and active.

I carry a handheld radio that allows me to vent frustrations at *#!>*&%# boaters without giving my identifying information to the local authorities.

You see, it's far easier to prosecute a radio violation based on MMSI info than it is to actually enforce laws on moving vessels when the *%&^#@!< has not a clue on right of way regulations, no wake, and on and on and on...

Why would someone with poor communicative/boating skills want themselves identified so easily by authorities?
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Old 02-03-2011, 10:07   #6
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Re: Resistance to DSC VHF

My GPS no speaky to my radio!..... AND my radio has no little red button! But I do carry a SPOT
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Old 02-03-2011, 10:09   #7
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Quote:
Originally Posted by rebel heart
For commercial vessels that's one thing, but you made a statement that you "integrate the DCS into your navigation system". Plenty of pleasure boats (mine included) don't have navigation systems other than charts and a handheld gps as well as other fixing instruments. That in and of itself seems to negate a lot of the benefit of DSC.

In the training videos I've seen, hailing someone via the MMSI takes much longer than simply grabbing 13 and hailing via voice.

DSC wasn't created because people wanted it; it was (as best I understand it) created by authorities to reduce voice traffic.

In regards to the "40 questions", I always thought a big part of that was to allow the USCG to fix your position by all those towers they erected in the last decade or so.

What does a DSC provide that a voice VHF if you know your position doesn't?
I will break this down a piece at a time.

Integration into a navigation system is a fringe befit not required for full use of DSC. Incoming DSC messages put messages on most chartplotters. Massage also appear in the VHF display. In your case you need only get the GPS NEMA RMC sentence data to the VHF which only requires a 2 wire connection.

My DSC has a phonebook in it to store MMSI which I think is common with class D VHF. I know the MMSI of folks I usually comm with. I preselect a working channel then select say Vesper in the phonebook and hit call. Even if the volume is turned all the way down on Vesper but the radio is on it rings and lets them know a comm is inbound. Since this is done over the reserved digital channel 70 no one else is aware of the call. With the DSC Auto Switch feature my VHF switches Vesper to my preselected working channel and we can talk once they turn up the volume. This offers some level of privacy if I select a working channel that is infrequently used in our area like say channel 71. BTW this type of call will go through even if someone's mic key is held open blocking voice hails.

It is all part of nations declareing Sea Area A1, AIS, and GMDSS. You can look these up on Google. Reduction in voice traffic is a secondary aspect as there is over congestion and DSC provides alternate mean for most voice comm including facilitating voice calls as explained above. This is also part of homeland security, terrorism, citizen health & safety, less cost and any number of there justifications governments give for these sorts of things.

No the 40 questions are a checklist developed by lawyers and are more about protecting the CG should a lawsuit develop than fixing your position. Beyond that it is intended to keep comm with the caller open in an emergency and get real time details, keep them calm and keep them engaged. If you have fully completed your MMSI application the mundane questions of the 40 questions are answered when you DSC VHF transits your MMSI as is done in all DSC traffic, they just look it up in a database only they and their international counterparts can access. I must stress that a free MMSI does not go into the international ITU database, only MMSI from the FCC are passed on to the ITU.

Like it or not people get rattled in an emergency, their higher brain (mammal brain) function shuts down. Now have the CG firing 40 questions about your boat (reg numbers, color, length, etc), equipment on it, where you are, where you are going, how fast you are going there, what the nature of the call is while you are still trying to operate the boat and it goes south real quick. A DISTRESS DSC alert sends your MMSI, your position and on some radios you heading and speed with the message automatically and continues to do so until the CG acknowledges the DISTRESS alert. Further anyone who has your MMSI, in this case the CG has it, that wishes to can poll your radio and find out where it is. If that is repeated enough you eventually will have a plot on them. Your radio can be polled for its position without you having to do anything if you know its MMSI. Have you ever listened in while someone tried to read their vessel reg numbers and/or lat/long over the radio, especially if there is engine, wind or other noise in the background or the comm link isn't real quiet? Now throw in a serious medical emergency or vessel in parle.

So yes DSC is a whole lot better than voice in this and a whole lot of other ways other than DISTRESS. I really do recommend reading the radio's manual for DSC features as I have only covered a few here, you paid for it why not use it the MMSI is free. I think you will be amazed with all the DSC features you paid for and are not using.

Why so hostile about getting you free MMSI, programing your radio and connecting it to a GPS with 2 wires? Is it because the gov didn't ask your opinion first or you resent excuses for yanking on the radio are being reduced?

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Mark Fay S/V Enough MMSI 367188830
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Old 02-03-2011, 10:13   #8
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Quote:
Originally Posted by capngeo
My GPS no speaky to my radio!..... AND my radio has no little red button! But I do carry a SPOT
Your VHF was purchased before the mid 90's.
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Old 02-03-2011, 10:26   #9
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Quote:
Originally Posted by Kettlewell
The problem is that you are constantly being annoyed by false DSC alerts, at least in the busy waters of New England. I have yet to hear a real alert. After awhile you just ignore the alerts. Too much crying wolf. For some reason my ICOM radio deprogrammed itself and lost my MMSI, and the only way to get it reprogrammed is to send it back to the manufacturer, which is a PITA.
False DSC DISTRESS alerts are the same as false voice alerts, only as another poster pointed out they know exactly who you are.

Now there is an ALL call feature that untrained people my use which could be abused and souls annoy. However once again the MMSI can be tracked to the annoyance source and even to a person.

Calls made from the radio phonebook will only go where directed and should not contact anyone else.

If your radio position is polled you will not know it. If you send your position you normally send it through the phonebook to a specific nickname/MMSI.

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Mark
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Old 02-03-2011, 10:36   #10
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Re: Resistance to DSC VHF

No, there are constant false DSC alerts that the Coast Guard often can't track down, possibly because the radios aren't registered or hooked up to a GPS. On a weekend in New England there are at least a couple of times a day when the CG has to call all around on CH 16 trying to determine who is setting off the alert and where they are located. The alarm sound is so bad that I sometimes turn off the radio if someone onboard is trying to take a nap--not what you're supposed to do, but like I said the alerts never seem to be real emergencies. Sometimes the alert just goes off for no apparent reason. I'm not against DSC. It's just that the current implementation is not ideal. I hope to soon get one of the updated 2011 VHF radios that just went on sale. They are supposedly much improved over the older DSC ones.
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Old 02-03-2011, 10:42   #11
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Re: Resistance to DSC VHF

Reb,

As I understand it, if your VHF is connected to the chart-plotter as you describe, then an incoming DSC distress signal would also indicate the senders position on the chart-plotter, thus vastly improving the ability to quickly reach them. Or, for that matter, someone else to reach you if you sent it. Yea?
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Old 02-03-2011, 10:57   #12
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Re: Resistance to DSC VHF

One problem not be addressed here is: YOU have to be Ten PerCent smarter then the toys you are playing with. And a lot of these Magellan want-a-be can't even find the on/off button for their toys.
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Old 02-03-2011, 11:03   #13
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Re: Resistance to DSC VHF

I wouldn't say I'm resistant to it.......The old Apelco radio still has stellar range and works. When it breaks I'll get the ais/dsc super radio but not a moment sooner.
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Old 02-03-2011, 11:13   #14
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Re: Resistance to DSC VHF

Quote:
Originally Posted by Greg S View Post
Reb,

As I understand it, if your VHF is connected to the chart-plotter as you describe, then an incoming DSC distress signal would also indicate the senders position on the chart-plotter, thus vastly improving the ability to quickly reach them. Or, for that matter, someone else to reach you if you sent it. Yea?
And a SPOT would tell where you were even after the boat had sunk. So, it's a toss up on what to really have.
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Old 02-03-2011, 11:14   #15
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Quote:
Originally Posted by Greg S
Reb,

As I understand it, if your VHF is connected to the chart-plotter as you describe, then an incoming DSC distress signal would also indicate the senders position on the chart-plotter, thus vastly improving the ability to quickly reach them. Or, for that matter, someone else to reach you if you sent it. Yea?
You are correct. In my case I have a 4 wire connection from my VHF below which goes through the NMEA MUX on my Raymarine AIS receiver to step up its bit rate so it merges the with the AIS NMEA data stream going to my E80 plotter in the cockpit and nav sta below. I use the VHF wireless mic in the cockpit for voice comm.

DSC messages such as SRM (Safety Related Messages) which are text messages usually from commercial vessel AIS appear on the plotter.

If someone send me their position or I poll someone's VHF for its position a pop up comes on the screen.

Naturally a DISTRESS alert puts a message on the plotter containing the information I have mentioned in other posts. I can then decide to make the position a waypoint if near by and head for it. Or if the alert comes from beyond range to shore I can relay it to another DSC VHF closer to shore or to the CG if in range. This is not done automatically I have to do it manually.

Other message also come up I just can't remember them all at the moment.

Your friend,
Mark
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