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Old 16-07-2015, 06:53   #46
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Re: Starting from scratch

Quote:
Originally Posted by thinwater View Post
Electronics threads are becoming just as amusing as anchor threads. More so, when you consider that you really don't need any of it, the way you need an anchor.

I've sailed a bunch of boats, and I always feel fine with whatever is available.

Personally, the OP lost me at "no electronics worth keeping, without mentioning if they worked or what they were. IMHO, I bet there was enough.
ROTFL. Thanks for that helpful comment.

Do you feel better now?
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Old 16-07-2015, 07:05   #47
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Re: Starting from scratch

So on that note...

For the benefit of Mr. Snide there will be a show tonight on trampoline...

I am buying a boat. This is my first boat. It is a "low end" boat. It is an old boat. I am 700 miles away from my low end, old boat. I have never seen it. I am hiring a surveyor, but that hasn't happened yet. The "advert" says:

Electronics:
Compass
Depthsounder
VHF

I am talking in short sentences for the benefit of the previous "oh so helpful" poster, who, having not a clue, decided he knew at least enough to make snide comments.

So, given that it an old, cheap boat, with the advert not giving glowing reports of what cool electronics are aboard, and given the extremely short list (and description) of electronics in the advert, I (must admit) made an assumption that the electronics were probably old and needed replacement.

Which I am doing.

And I felt no particular need to say ANY of this until Mr Snide decided to post. It didn't seem particularly relevant to me.

So (snide comments aside), what's the real deal with AIS and a new (to me) boat.
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Old 16-07-2015, 15:14   #48
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Re: Starting from scratch

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Originally Posted by jwcolby54 View Post
OK, be patient here, I have never done this. Isn't my MMSI number issued when I register an AIS device with the coast guard? And isn't that process the "this is my boat name, length, weight etc" process?

So at the moment I don't have an MMSI number. That is my point here. I don't yet own a boat. I am in the process of getting a survey done and IF it floats, sails and motors then I am on the hook to buy it, but it is not yet mine.

The boat is 700 miles away and I have to get there and sail it home. To do that I want to buy a new VHF (with built-in AIS receiver and DSC) and new VFH HH (with built-in AIS and DIS) to take on board before I sail home. Both of these VHF radios have everything required to do the emergency "push a button and transmit your AIS info in an emergency message".

But I have never registered a boat in my name with the coast guard. I don't own a boat. Yet.
Your MMSI number is issued by the FCC not the USCG. If your boat will always be within US waters then you can get the MMSI from BoatUS, and a few other organizations, for free. Otherwise if you'll be operating internationally, including Canada, you'll need an FCC Ship Station License.

The MMSI is used with both the VHF radio and AIS. However, the VHF radio only has the MMSI. The AIS has your callsign, boat name, type, and position of the GPS antenna (you can actually just put the overall beam and length).

You can program the MMSI into your VHF radios yourself. Your AIS must be programmed by the dealer or installer.

You don't register your AIS or VHF with the USCG or anyone. The FCC database has your MMSI and a few other details about the boat so it can be looked up there. The AIS transmits your information so no lookup is needed.

Assuming you need an FCC license, rather than the domestic-only MMSI, here's a link to some info about the process: FCC: Wireless Services: Ship Radio Stations: Licensing

You do it all online by filling out form 605 and paying the fee. You do this after you have purchased the boat even if it already has an FCC Ship Station License because it's not transferable. It typically takes just a few days for the FCC to issue a new callsign and MMSI.

Hope that helps. If not, just ask.
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Old 16-07-2015, 20:03   #49
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Re: Starting from scratch

Thanks Jeff, that does help.

It seems that the VHF radios can be one time programmed with an MMSI number. If I decide to change or make a mistake, then the radio has to be reprogrammed by the manufacturer.

From what I can determine I cannot even apply for an MMSI until I own the boat because... the process of applying for the MMSI asks for all of that boat information. The MMSI number seems to apply to one specific boat. Why it would be non-transferrable is beyond me since it applies to the boat. It should transfer with the boat to the new owner.

According to this very official looking website:

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

"Maritime Mobile Service Identities (MMSIs) are nine digit numbers used by maritime digital selective calling (DSC), automatic identification systems (AIS) and certain other equipment to uniquely identify a ship or a coast radio station. MMSIs are regulated and managed internationally by the International Telecommunications Union in Geneva, Switzerland, just as radio call signs are regulated."

Further to that:

"In order to obtain an MMSI, mariners required by regulation to carry a marine radio and those who travel outside the U.S. or Canada to foreign ports must apply to the Federal Communications Commission for a ship station license or an amendment to a ship station license."

That applies to me as I intend to travel internationally.

Further to that:

"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 diverís radio) should be assigned a unique 9-digit number in the format 81M2I3D4X5X6X7X8X9. 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."

So...

It seems that the FCC issues the MMSI, and it appears to be BOAT specific. The MMSI is in fact programmed into the VHF as well as any Hand Held(s) used on that boat.

The MMSI is actually stored in an INTERNATIONAL database somewhere (from other readings I have done) and THAT database contains other boat and MMSI owner contact information, for use in search and rescue operations. MMSI numbers issued by Boatus etc are NOT stored in the international database, thus cannot be found by S&R operations outside of US waters.

So today I purchased the Standard Horizon GX2200. This radio has integrated 66 channel GPS / AIS (reception) / DSC stuff. Used standalone, it is capable of completely handling AIS reception and DSC Reception and transmissions.

I also purchased the Standard Horizon HX870 which is their Hand Held version of the GX2200. Complete with GPS / AIS / DSC it can do much the same stuff, also entirely standalone.

Once I own my boat, I can apply for my MMSI number and I can program it into both of these radios. I just need to get it (the programming) right the first time.
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Old 16-07-2015, 21:09   #50
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Re: Starting from scratch

Quote:
Originally Posted by jwcolby54 View Post
The MMSI is actually stored in an INTERNATIONAL database somewhere (from other readings I have done) and THAT database contains other boat and MMSI owner contact information, for use in search and rescue operations. MMSI numbers issued by Boatus etc are NOT stored in the international database, thus cannot be found by S&R operations outside of US waters.
Your info is correct except this part. MMSI's are administered separately by each country and other than countries being allocated blocks of numbers (called the MID) there is no international registry. In the US it is the FCC that assigns them and for domestic-only they have delegated sets of numbers to BoatUS, etc. I believe BoatUS MMSI's will not appear in the FCC database. But assuming international, the FCC will issue it to you as a regular part of your Ship Station License which you can apply for once you own the "ship".

Keep in mind that the MMSI is not the same number as is used with an EPRIB. Those are assigned by the EPRIB manufacturer but require registration by the owner and the registration databases are administered by country (NOAA in the US). EPRIB registration is unrelated to FCC or MMSI issuance and those databases are used for Search and Rescue purposes.
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Old 16-07-2015, 21:41   #51
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Re: Starting from scratch

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Originally Posted by jeffrobbins View Post
Your info is correct except this part. MMSI's are administered separately by each country and other than countries being allocated blocks of numbers (called the MID) there is no international registry. In the US it is the FCC that assigns them and for domestic-only they have delegated sets of numbers to BoatUS, etc. I believe BoatUS MMSI's will not appear in the FCC database. But assuming international, the FCC will issue it to you as a regular part of your Ship Station License which you can apply for once you own the "ship".

Keep in mind that the MMSI is not the same number as is used with an EPRIB. Those are assigned by the EPRIB manufacturer but require registration by the owner and the registration databases are administered by country (NOAA in the US). EPRIB registration is unrelated to FCC or MMSI issuance and those databases are used for Search and Rescue purposes.
Well, I apologize but I have read about 47 different versions of this info over the last week as I have struggled to get it straight.

My understanding is that there is in fact an "international database" of these numbers. Yes, each country gets their own range of numbers, but those numbers end up eventually being registered in that "international" database, and is then used if I (an american) ends up asking for help out in the middle of (for example) the Indian Ocean. The S&R organization that responds goes to that international database to "look up my number" to determine who I am, who to contact, how big my vessel is etc.

Someone here in the US (the FCC???) ends up posting "our" numbers out to the international database.

See:

About MMSI

"Global Maritime Distress & Safety System (GMDSS) was developed by the United Nations agency, the International Maritime Organization (IMO), as the internationally accepted system of coordinated radio communications (ship-to-ship and ship-to-shore) using satellite and terrestrial networks for commercial vessels.

The GMDSS consists of several systems, some of which are new, but many of which have been in operation for many years. The GMDSS radio carriage requirements depend upon the ship's area of operation, rather than its tonnage. The system also provides redundant means of distress alerting, and emergency sources of power. Recreational vessels are not required to carry GMDSS equipment; however it is strongly encouraged for all vessels on international voyages or traveling greater than 25 nm offshore because of the very efficient communications and rapid distress response. All vessels near shore and on the high seas are strongly encouraged to apply for an MMSI number to allow the use of Digital Selective Calling (DSC) in the case of an emergency.
Automatic Identification System (AIS) has become an important element of the GMDSS monitoring system because of its ability to provide immediate and accurate contact between vessels. To help with the coordination of vessel identity AIS users use the same MMSI numbers assigned to the vessel for GMDSS purposes. The system is backwards compatible with DSC, allowing shore-based GMDSS systems to affordably identify and track AIS-equipped vessels, and is intended to eventually replace the existing DSC-based transponder systems. "

Thus it appears (to me at least) that the MMSI is in fact international in nature (and origin), that the FCC administers the assignment of said numbers in the US, but that ultimately it is stored in an international system. HOWEVER... the "US only" numbers assigned by USBoat and the like are NOT stored in the international database. It appears (to me) that the coast guard holds, in their own database, all numbers assigned to the US, as well as "us only" numbers. But it also appears (to me) that as new "international" numbers are registered in the US, somebody (FCC? Coast Guard?) pushes those out to the international database for use in S&R operations outside of the US waters.

Basically, out in the middle of the ocean, it is up to some nebulous international somebody to figure this stuff out. The coast guard is only tasked with handling territorial waters of the US. But the international somebody can't handle my number if they don't have it.

Sorting this all out is a non-trivial task.
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Old 16-07-2015, 22:06   #52
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Re: Starting from scratch

I am not aware of an international database of MMSI numbers or who would keep it. When you apply for an MMSI there is virtually no useful rescue information about your boat. It's essentially just a radio callsign.

Your AIS transponder transmits who and where you are. And when you press the emergency button on your VHF it transmits your position to the vessels nearby or USCG if you are within range. But if you are in the middle of the ocean neither of these will be heard unless there is someone with range.

EPRIB's work differently using satellites which relay to mission control which is able to check the registration database, contact the proper rescue coordination center, retrieve the registered owner's emergency contact details to verify the emergency, and subsequently dispatch search and rescue resources.
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Old 17-07-2015, 13:10   #53
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Re: Starting from scratch

jw,
Please allow me to preface this by making it clear that I am really trying to be helpful....and I will keep any comments to the very end....

But, also....
To be completely honest here, I sort of assumed that your prospective boat had a working / accurate depth sounder....because that, a compass, and some charts, are actually all you'd really need to get your "new-to-you" boat home...
If you desire more electronics, etc., that's fine....here below is some honest, helpful info regarding your new DSC Radios....


1) First off, Jeff has given you great info....and he is mostly correct (save for the fact that the ITU does maintain the international MMSI # database)....
Remember, Jeff's company designs, builds, and sells AIS transponders.....Jeff doesn't work for Standard Horizon....so, it's certainly above 'n beyond him trying to help your sort out some non-AIS stuff, from some other company's gear!!!
Kudos, to you again, Jeff!!

Here is a link to the public-accessible part of the ITU database....(the individual gov't RCC's have full access, that we are not granted...)
Particulars of Ship stations



2) Secondly.....as for explaining all of this, etc., I'm a bit hesitant to actually post here and actually answer your questions, as you may take offense and call some of my comments "snide"....so, before reading more, please understand I am really trying to be helpful...



3) Third....
You have not made any mention of an AIS transponder, so there is nothing (except for your MMSI #) to program into any of your new radios....and no "AIS" for you to deal with at all...

Please read the portion of your posting, that I have added the bold-type to...
Quote:
Originally Posted by jwcolby54 View Post
OK, be patient here, I have never done this. Isn't my MMSI number issued when I register an AIS device with the coast guard? And isn't that process the "this is my boat name, length, weight etc" process?

So at the moment I don't have an MMSI number. That is my point here. I don't yet own a boat. I am in the process of getting a survey done and IF it floats, sails and motors then I am on the hook to buy it, but it is not yet mine.

The boat is 700 miles away and I have to get there and sail it home. To do that I want to buy a new VHF (with built-in AIS receiver and DSC) and new VFH HH (with built-in AIS and DIS) to take on board before I sail home. Both of these VHF radios have everything required to do the emergency "push a button and transmit your AIS info in an emergency message".

But I have never registered a boat in my name with the coast guard. I don't own a boat. Yet.
And, this part of your other recent post....
Quote:
Originally Posted by jwcolby54 View Post
So (snide comments aside), what's the real deal with AIS and a new (to me) boat.
And again, if you can take what I say here as constructive and understand my attempt to be helpful, then read further....if not....well, at least I tried...

The fact is that the radios you describe are NOT AIS Transponders, do NOT have any "AIS data" to transmit in an emergency or otherwise, and there is NO "AIS" for you to "deal with" in using these radios...
These are VHF-DSC radios, NOT "AIS units"!!!
(yes the GX2200 does have a built-in AIS receiver, but that's like saying I bought a ShortWave receiver and now don't know how to program my smart-phone apps into it....you know, kinda' "apples" and "oranges"....)

You are confusing a "VHF-DSC message" (Distress or otherwise) with "AIS data".....they are two completely separate and distinct systems and collect/send different data....
Since you have not mentioned an AIS transponder, you do not have any "AIS data" to transmit, nor any way to transmit it....


You were doing well with the USCG pages....but went way off track trying to read others interpretations of things (don't bother with mmsispace!)
Fact is, AIS is NOT a replacement for DSC, nor is DSC comparable to AIS....
They are two totally different systems, for two totally different applications....while the both use parts of the Marine VHF radio spectrum, and both send data, that is where the similarity ends!
(AIS is not replacing DSC!)


Since you do not have an AIS transponder, there's no need to get bogged down in all of that....but you REALLY should learn about DSC, how it works, why it works, and why you may find it helpful...
So, if you wish to learn about DSC, there are some videos that explain it very well....
They are FREE...nobody is promoting anything at all (except for DSC)....they are just informative videos, that will help you....

Have a look here...particularly at video #1 and video #10 (and if you don't have time to watch them all, please watch #1, #10, and have a look at #13, #14, and #15...)
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX






Although the major thrust of the playlist is for long-range HF-DSC, the videos (1, 10, and 13, 14, 15) that I mention specifically will not only explain everything well, but they also deal specifically with VHF-DSC...


I hope you find both this posting and the videos to be helpful....



And, if you desire multiple, detailed and prioritized lists of "electronics" to install on-board, based on both budget and planned cruising/sailing areas, there are some recent threads here that will help...

Have a look!!



As an example, here's a discussion from just two weeks ago...
My first post: Advice on Basic Electronics.




And, have a look here as well...(these are all DIFFERENT posts, even if their names show the same here!)
Cruising Comms Set Up!


Guide to Marine Electronics


Guide to Marine Electronics


Communications equipment


Communications equipment


Communications equipment


The Perfect Setup


Have to haves and wants


AIS...all in one radio or computer/opencpn




4) Now that I got all of that out of the way....
If you don't mind, I'd like to politely defend "thinwater"....
I especially agree with his statement "Electronics threads are becoming just as amusing as anchor threads."....
JW, your info shows a Morgan Out Island 33....and shows you are located in North Carolina.....
And, you mention that you haven't bought the boat yet, but it is 700 miles away....
So, unless it is in the central/southern Bahamas, we can assume that after purchasing it, you'd be sailing it home along a coastal area???

If all the above is true, then the single most important piece of "electronics" on board is going to be a working (and accurate) depthsounder!!!!
Bar none, a working depthsounder.....a compass, and some charts, will get you home safe, and keep off the bottom....
(yes, many will also say a GPS receiver, even a small hamdheld GPS.....but a GPS receiver can't tell you the depth of the water!!! And a depthsounder and some charts can allow you navigate your way home, and keep from running aground..)

Understand that MOST objects / boats / etc. out in/on the water do NOT have an AIS transponder, so you need to use your eyes to look out, a chart and DR / coastal piloting, to fix your position, and a compass to allow you to steer to your desired destination(s)....

If you incorporate "electronics" into the mix, that is fine!!!
(I've made a good living in the electronics industry)
But, in my opinion, based on my almost 50 years of sailing/cruising experience, multiple Atlantic crossings, years of gunkholing thru the Bahamas, multiple cruises thru the Caribbean, etc. etc. etc....the single most important piece of "electronics" on-board is a depthsounder!!
(in second place, regarding on-board electronics, is a well-installed VHF-DSC radio....and in third place would be a good GPS....)
But, remember.....without an experienced person navigating / sailing the boat, none of the electronics matter....

I think the above points are what "thinwater" was trying to convey....


In any case, while there is a LOT more, that's all for now....
I do hope I helped...

Fair winds...

John
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Old 17-07-2015, 15:01   #54
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Re: Starting from scratch

I don't want to sidetrack away from the really important points you are making John, so please lets keep the thread there... but did want to thank you for pointing out the MARS database. I wasn't aware that the ITU was keeping it so glad to learn about it.

There's very little info there about each vessel. Not at all like the EPIRB database. When I look up my own boat's US-issued MMSI it has just the name and class=pleasure. Presumably the secure access site also has my address/phone at the time the entry was last updated in 2001. That's not a big surprise because the FCC form 605 doesn't gather any info other than the name of the vessel and applicant name/address.

But when I lookup each of my NZ MMSI's none are there. I then looked up a bunch of other valid NZ MMSI's that I can see in my vicinity and none are there. I did see a few NZ Class A MMSI's but there's an 80m tanker nearby and it doesn't appear in the database. In any case, the database is certainly useful but not complete. But now I'm curious so I'll get in touch with people I know at Maritime NZ and Radio Spectrum and ask them about it and report back. (Those government agencies are roughly analogous to USCG & FCC here).

Now, back to the real thread...

In my own experience, not as an AIS designer but as a cruiser, I agree completely with you John...compass, depthsounder, good chart, VHF & GPS (marine GPS not phone). That will get you anywhere. I've sailed lots of miles with nothing more. I include GPS though because it costs so little and is kinda silly not to have it.
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Old 17-07-2015, 19:55   #55
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Re: Starting from scratch

Quote:
Originally Posted by ka4wja View Post
jw,
Please allow me to preface this by making it clear that I am really trying to be helpful....and I will keep any comments to the very end....
ka4wja...

Let me just say I was responding to this:

Quote:
Electronics threads are becoming just as amusing as anchor threads. More so, when you consider that you really don't need any of it, the way you need an anchor.

I've sailed a bunch of boats, and I always feel fine with whatever is available.

Personally, the OP lost me at "no electronics worth keeping, without mentioning if they worked or what they were. IMHO, I bet there was enough.
OK, so what does this say exactly?

Quote:
I've sailed a bunch of boats, and I always feel fine with whatever is available.
Absolutely irrelevant to MY thread. Understand that I came here to discuss outfitting a boat with new electronics. This really is MY thread, as the OP.

So this guy is superman. I am not. I have made it clear that I have never even owned a boat before. Of course it is unlikely that he even read the thread.

Quote:
Electronics threads are becoming just as amusing as anchor threads. More so, when you consider that you really don't need any of it, the way you need an anchor.
I am happy that this guy is amused, but is it necessary to show up and interject this crap? Really? What does this do to further anyone's education?

And finally:

Quote:
Personally, the OP lost me at "no electronics worth keeping, without mentioning if they worked or what they were. IMHO, I bet there was enough.
OK, REALLY?

As far as I am concerned this entire post, from start to finish, was condescending drivel with absolutely NO PURPOSE other than to help some yahoo with low self esteem feel better about himself. He pats himself on the back a couple of times and tells us how amusing the thread is and how he is sure (not sure HOW he is sure) that the electronics on board are entirely sufficient.

OK. Right.

So no, I am not going to go off on you or your post. Your post was chock full of useful information.

As opposed to this other yahoo. I have no use for folks dropping into threads to interject "I'm so cool" kinda crap and leaving. From over here, it WAS snide from start to finish.

OK, I'm done now.
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Old 17-07-2015, 21:01   #56
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Re: Starting from scratch

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Originally Posted by ka4wja View Post
jw,
Please allow me to preface this by making it clear that I am really trying to be helpful....and I will keep any comments to the very end....
Very much appreciated too.

Quote:
To be completely honest here, I sort of assumed that your prospective boat had a working / accurate depth sounder....because that, a compass, and some charts, are actually all you'd really need to get your "new-to-you" boat home...
And I assume nothing. This is an inexpensive, low end boat. I am paying $10K not $200K. As I mentioned in my response to Thinwater, the ad literally tells me nothing except

1) "VHF" (they had these in 1990)
2) "Compass" (I can see a picture of a magnetic compass on the cockpit wall).
3) "Depth Finder". I can see something that looks like it MIGHT be such a thing, in the photos, but no details.

So, just me, if I am selling something, and it has really cool something that raises the price, I am going to throw names around. The very fact that the names are "generic" tells me that... well, the PO was not particularly proud of the electronics. I do know that he has bought a new boat. Maybe this boat had cool stuff and he took it with him. Maybe he had some old stuff in the bottom of a drawer he "threw in". How can I tell?

And finally, what will "get you home", having sailed for some period (of many years?) and what you are comfortable with, is entirely different from what someone who has never owned a boat before will be comfortable with.


Quote:
Here is a link to the public-accessible part of the ITU database....(the individual gov't RCC's have full access, that we are not granted...)
Particulars of Ship stations
So notice that MMSI is one of the key pieces of info. And it is my understanding that to get the MMSI you provide exactly the same info that you would otherwise program into your AIS transponder.

Now, it is also my understanding that the MMSI is in fact in a database, associated with all of my other information. So when I flip up that little piece of plastic and press the "help me I'm sinking" button, my MMSI is transmitted. That MMSI (AFAICT) "equates to" the AIS information that an AIS transponder would have self contained, at least if the message is picked up by any S&R agency. They look up the MMSI I am transmitting in their database and voila, they have my AIS info.

Or that was how I thought it was working.

Quote:
2) Secondly.....as for explaining all of this, etc., I'm a bit hesitant to actually post here and actually answer your questions, as you may take offense and call some of my comments "snide"....so, before reading more, please understand I am really trying to be helpful...
And you are being helpful, as opposed to Thinwater who was in no way helpful.

Quote:

3) Third....
You have not made any mention of an AIS transponder, so there is nothing (except for your MMSI #) to program into any of your new radios....and no "AIS" for you to deal with at all...
If you go back to my original post:

7) Vesper Marine XB-8000 AIS transponder - Provides GPS 1 data (primary). Provides AIS 1 data (primary).

Quote:

The fact is that the radios you describe are NOT AIS Transponders, do NOT have any "AIS data" to transmit in an emergency or otherwise, and there is NO "AIS" for you to "deal with" in using these radios...
These are VHF-DSC radios, NOT "AIS units"!!!
Yes I understand that, but if you press the "I am sinking" button, then you transmit your MMSI number and THAT (AFAICT) is exactly and precisely your AIS information, or at least keys into their database to let them get that info.


Quote:
You are confusing a "VHF-DSC message" (Distress or otherwise) with "AIS data".....they are two completely separate and distinct systems and collect/send different data....
Again, my understanding is that DSC is two completely different things in one VHF radio.

1) A system for "digital selective calling" which takes your (someone I am listening to) MMSI number and uses that as a phone number (as it was explained to me) to respond to them precisely and exactly, i.e. "CALL THEM". But it uses the MMSI to do that.

2) An emergency system for sending request for help messages. That ALSO sends the MMSI, but now it is used by the S&R receiving station to "look me up" in a database and find out who I am, my AIS information in the AIS database.

So in case #1, the MMSI is nothing more than MY "phone number" when I transmit it in a normal DSC call. And I use YOUR MMSI to cause your radio to "wake up" when I make a call to your MMSI number.

Of course I may be so totally off base as to be unreachable, MMSI number or not!

Quote:
Fact is, AIS is NOT a replacement for DSC, nor is DSC comparable to AIS....
They are two totally different systems, for two totally different applications....while the both use parts of the Marine VHF radio spectrum, and both send data, that is where the similarity ends!
(AIS is not replacing DSC!)
Uh yep.


Quote:
4) Now that I got all of that out of the way....
If you don't mind, I'd like to politely defend "thinwater"....
Why?

Quote:
I especially agree with his statement "Electronics threads are becoming just as amusing as anchor threads."....
OK, so go drink a cup of coffee and read a book.

Or make a useless self aggrandizing post that adds nothing to the discussion?

Personally in that case, I would go read a book.

Quote:
etc. etc. etc....the single most important piece of "electronics" on-board is a depthsounder!!
(in second place, regarding on-board electronics, is a well-installed VHF-DSC radio....and in third place would be a good GPS....)
Got it. And I really really do appreciate your thoughtful and data filled response.

Quote:
I think the above points are what "thinwater" was trying to convey....
And to this point the only thing he actually conveyed was that he needed to take his meds and a nice long nap. Cause what he actually said was drivel.

So do not think I am irritated at you in any way. I am not.

I do need information on how all this actually works. From what I can tell (I am a database analyst), the MMSI number is nothing more than a key into a database for rescue purposes, and figuring out WHO YOU ARE. It has been hijacked to use as a "phone number" for DSC, kind of like my SSN has been hihjacked for purposes totally unrelated to what it was intended for.

And I long ago watched a bunch of "here's what DSC is and how to use it" youtube videos by BoatsBeachesAndBars, and some guy who did a dozen videos specifically about DSC. Can't find him right now.

I'm getting there, slowly but surely.

Thanks again for taking the time to educate me further.
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Old 17-07-2015, 21:20   #57
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Re: Starting from scratch

Quote:
Originally Posted by jeffrobbins View Post
There's very little info there about each vessel. Not at all like the EPIRB database. When I look up my own boat's US-issued MMSI it has just the name and class=pleasure. Presumably the secure access site also has my address/phone at the time the entry was last updated in 2001. That's not a big surprise because the FCC form 605 doesn't gather any info other than the name of the vessel and applicant name/address.
I have to say the coherency of the information out there (available to me) is abysmal.

Quote:
Now, back to the real thread...

In my own experience, not as an AIS designer but as a cruiser, I agree completely with you John...compass, depthsounder, good chart, VHF & GPS (marine GPS not phone). That will get you anywhere. I've sailed lots of miles with nothing more. I include GPS though because it costs so little and is kinda silly not to have it.
And IMHO, the GPS is critical. When I hit the "I'm sinking" message, if I have a GPS, my exact location is inserted into that message in addition to my MMSI. The MMSI says "who I am", the GPS says "where I am".

Furthermore, it is my understanding that if I send a DSC to someone, my MMSI and GPS is sent in that VHF transmission as well. So now the person receiving my transmission can come to me, or know where I am.

I do understand that the VHF is NOT an AIS transponder. But the way I understand it, when I hit the panic key, I transmit my GPS and MMSI number which the S&R use to find me.


This is interesting. Kind of touches on many of these things.

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Old 18-07-2015, 06:01   #58
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Re: Starting from scratch

JW,
You're very welcome....and please accept my apologies on two fronts...

First, for taking your more recent post (mentioning your newly purchased VHF-DSC radios) as the most up-to-date plan...rather than going back to the beginning and rehashing what has already been written....as I thought you had "moved-on", and simply decided to install the new radios in order to get your new boat home....(and then later deal with an electronics outfit)

And second, for not having the time to take you thru everything one point at a time....(which is why I recommended you watch the videos, read over the referenced threads, and then refer to some of the USCG info for further clarification.)




It appears that you did not watch the videos, read the other threads, nor go back to the USCG pages....as these would have cleared up all of your confusions...
So, the best advice I can give you, is to do those things... and I think you will find the information just as useful whether it was written two weeks ago, two months ago, or two hours ago....




I do hope this helps...


Fair winds..

John
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Old 18-07-2015, 07:07   #59
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Re: Starting from scratch

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Originally Posted by ka4wja View Post
JW,
And second, for not having the time to take you thru everything one point at a time....(which is why I recommended you watch the videos, read over the referenced threads, and then refer to some of the USCG info for further clarification.)

I do hope this helps...


Fair winds..

John
Thanks John.

I have to say that while Youtube is very cool, wonderful and useful, it is also time consuming and less useful than written stuff.

As an example, I have watched several of CaptainJohn49's videos. Take video 1:

DSC - Digital Selective Calling. What is it? How does it work? How do you use it?

It takes about 12 minutes to really impart about 3 paragraphs of information. He says a bunch of stuff, several different times, and even then he never gets down to the meat of the issue, which is "what is actually SENT in these messages". He tells us what the messages are, he tells us how to send them (on that specific radio) but nowhere does he actually explain WHAT INFORMATION IS SENT in each of those messages, just a kind of "big picture" kinda sorta might be something useful explanation. So I watched this exact video (last month!!!) and never came away with very much useful info.

John, I have been reading threads on forums, and watching YouTube videos for a month, and I STILL apparently don't get it. And I am not dense, my job is assimilating highly technical information.

My background is electronics. I started in 1968 (9th grade) learning electronics from the ARRL handbook. I read it until I had it down. I never got my Amateur Radio license because I never quite got my Morse code high enough, though I got close.

After high school I was trained by the US Navy to fix computers and I did that as my job until the mid 1980s. Reading schematics and using o'scopes to find and replace the exact chip causing a problem in a wide range of computer boards.

So I know electronics and computers. And since the mid 1980s I have been a programmer and database analyst. I understand this stuff at a level (relatively) few folks in the world understand this stuff. But I do not understand DSC to this level, and I am not getting there very quickly.

Back to the issue, he dances around all the real good stuff. Maybe he doesn't know it. He discusses frequencies. Cool, and I understand what frequencies mean down to the wavelengths and tuning antennas and circuits to receive them, but that is not really useful since it is a "channel" that I select, I do not "tune" my radio like I did in the old days.

But more importantly (to me), WHAT DATA IS SENT!!!

He mentions these "five messages" which are DIGITAL. Strings of bytes sent (and of course received from others transmissions). WHAT ARE THOSE BYTES? What is sent for each of those five messages? That is never explained. And I listened closely!!! He mentions that I can send stuff that sounds like I have to program bytes in there (which channel I want to meet up on for example) but he is so busy talking he never actually ever discusses the good stuff.

Now listen closely to that first video at 8:30 where he tells us that we MUST HAVE (repeated twice) a separate DSC emergency antenna to RECEIVE the emergency calls on a bunch of different frequencies. I have to tell you that I completely missed this on my first TWO listenings to this specific video. And furthermore, this fact is never mentioned in the sales literature for ANY of the radios out there that can receive this stuff.

Which reiterates my "complaint", that Youtube videos, while nice, are just too long and full of random comments by whoever is making them. This CaptainJohn guy does a good job, but a two page written analysis of this would be SOOOOOO much better.

So fine, I will watch all of the videos (hours of stuff) to get (maybe, if I don't miss some critical piece) what should be written down somewhere, in a concise and edited format, preferably in a sticky, in the top of this forum.

I do appreciate that you took the time to respond to my obvious confusion with the suggestions that you gave me. I will go listen to all this stuff. I promise.

But I will also say that I have already watched about this many videos about the subject, and read about this many threads (or more!) and still apparently don't understand the core information. Which is damned discouraging, and doesn't give me much confidence that I will "get it" from all of the stuff that you recommend.

Telling me to go watch FIVE videos and then read through TEN different threads tells me that you actually care and I am grateful for that.

May I suggest (beg actually) that, since it appears that you and JeffRobins really know this stuff already, WRITE THIS INFORMATION DOWN and get it placed in a sticky. I will do the edit! You will have done the community an enormous favor.

Anyway, many thanks, and off I go to watch and read your suggestions.

jwc
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Old 18-07-2015, 07:50   #60
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Re: Starting from scratch

And John, I see it was you who wrote those FINE videos that explain this mess. I was actually reading through (and watching your FINE videos ) for a while now. I had found your STICKY and was working through it, but didn't connect the dots that the person responding in my thread was the same FINE individual that was responding to my thread. Whooo boy!

In my defense, I do not learn well from videos. I have a short attention span (ADHD) so I get distracted just when something important is about to be said. I do watch Youtube but I tend to have them playing as I read other information. Did I mention ADHD?

So (for me) written information is how I learn best. In addition, when I am in my bunk, 50 miles off shore, I cannot watch YouTube videos so I will be reading written information.

But I do very much appreciate that you made these videos.

And don't worry, I have washed all the egg off my face.

And BTW, I found this:

http://www.vhf-dsc.info/

Which does a good job of succinctly summarizing and explaining this stuff.

And I now understand that when I am generating a DSC message, I am simply stepping through menus which are "filling in" the pieces of the behind the scenes message (which I finally "got" from your video and the other one from the "class" video).

Got it.

And finally, you have a most impressive comms station. Mine will have all that stuff some day.
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