Miami 2014 comms #2: VHF, AIS & the app connection

... written for Panbo by Ben Ellison and posted on Feb 25, 2014


There is still an amazing number of boats that can't use the excellent DSC distress feature that's been built into every fixed VHF marine radio sold in the U.S.A since 1999. Their radio either hasn't been interfaced with a GPS or hasn't been programmed with the owner's MMSI number, or both. I've heard Coast Guard rescue center personnel report that a DSC alert can work beautifully to quickly identify and locate a boat in trouble, but that they rarely see valid DSC alerts. So before discussing advances in VHF (and AIS), let's note how companies like Standard Horizon and Icom are helping to make working DSC a pervasive reality (finally)...

First note the "WARNING! DSC NOT AVAILABLE" squeezed onto the Eclipse DSC+ screen above, and particularly how the operator must acknowledge the warning before using the radio. Standard Horizon's Jason Kennedy tells me that some radios on the market don't yet include this mandated acknowledgement, and I agree that they should (and that boaters who complain about it deserve a lecture on the costs and frustrations of failed search and rescue operations). Kennedy remains a little miffed that Standard Horizon recalled radios last year to fix much more minor interface issues than this, but the authorities have apparently still not insisted that all manufacturers catch up with the improved DSC interface requirements of ITU-R M.493-13 (explained here on Panbo).


The DSC warning can be more detailed on the big screen of the new Standard Horizon Matrix AIS/GPS, but perhaps more important is that little GPS antenna bump at upper left. The sign should read "VHF with AIS and GPS," which of course means that no installer has to make an annoying NMEA 0183 bare wire connection for this radio to know where it is and be able to share that knowledge with the Coast Guard (or your nearby boating friends). The internal GPS, still unique to Standard Horizon in fixed radios, also means that DSC can work even when no other electronics on the boat are powered up.


Also impressive was the Icom M506 recently detailed here. The Miami show was my first chance to fool with the user interface Icom has been using in new models, and I think it looked especially good on that giant screen. Entering your MMSI seemed very easy, for example, and I'm happy to add that some influential people in the boating world are questioning the strict rule, making it impossible for a boater or installer to change a radio's own MMSI when a vessel changes hands (or operating areas in some cases). It seems like an unnecessary annoyance when you think it through, and I hope to report soon on a movement to change that rule.


For the M506 models that include a NMEA 2000 interface, getting GPS to the radio should be plug and play simple, and the same connection should also allow DSC calls to appear on chart plotters (another reason to get that distress button working). M506 models with AIS receivers should be able to distribute target info, including AIS MOB alerts, over N2K (and/or NMEA 0183) and hopefully, the models without AIS receivers will still be able to display it and place direct DSC calls to targets if they see AIS data coming in through a NMEA port. So, it was nice to discover that the M506 has a full screen AIS radar-style display option, as well as the partial screen one you'll see elsewhere. 


The Simrad RS90 black box VHF system seems quite similar to the RS35 radio and HS35 wireless mic combo introduced in 2012, except that the 90 can support four fixed mics and two wireless ones. It also has a replay-last-call feature similar to that included on the Icom M506. This system could have gone in the entry about Miami glass bridge advances and is obviously designed to compete with the Garmin VHF 300 series and the modular Ray260. Apparently, the RS90 will not ship with DSC calling to AIS targets, but "future features include DSC calls to AIS targets from handset and compatible MFD plus advanced intercom facilities." The RS35 (I'm about to finally test) is in the same situation, I think.


McMurdo now offers AIS transponders and receivers, including this Class A M5 color screen model, which is purportedly the first transponder {correction: first Class A transponder} to show AIS MOB alarms (like the many MFDs that can alarm on Personal AIS Beacons built by McMurdo and others). Incidentally, the Kannad R10 AIS MoB Beacon is now sold as the McMurdo SmartFind S20, which seems to fit the large ambitions of the newly formed McMurdo Group.  


While McMurdo's AIS transponders seem to be sourced from Alltek Marine Electronics, they don't yet offer the Camino-108W Class B model sold under Alltek's own Amec brand. What's noteworthy about the 108W is that it has both NMEA 2000 and WiFi interfaces, which means it can potentially supply tablet charting apps with AIS, GPS, and most any other boat data available on a boat's N2K network. Alltek already has some expertise at N2K messaging and Milltech Marine already offers the Camino 108W, but so far the manual doesn't say anything about which apps can get what data over the WiFi.


Meanwhile, DigitalYacht just announced NavLink US, which is apparently a version of the recently reviewed SeaNav app that DY will support in conjunction with its WiFi AIS receiver and NMEA WiFi bridge devices. DigitalYacht founder Nick Heyes has put together an excellent 10 minute YouTube presentation that explains how these devices and NavLink can all work together. (Speaking both to boaters and installers, Nick also makes a good case for how this sort of WiFi boat data link can bring new life to even older marine electronics systems.)


Of course, Vesper Marine also sees how a WiFi Class B AIS transponder can serve as the gateway between apps and AIS/GPS data as well as other boat data. I've already experienced some of that while testing the WatchMate Vision, and I returned from Miami with the perhaps under-appreciated WatchMate XB8000 to test. I'm looking forward to seeing how Vesper now passes along "a wide range of wind, depth, speed, heading, log and temperature PGN's." In Miami I also saw the ambitious new app NavPlay looking good in a demo. NavPlay will support Jeppesen C-Map charts and already has a marketing partnership with Vesper. It looks like the two companies have a complete iPad WiFi transponder solution that can even integrate with autopilots.

Finally, Simon Tucker -- CEO of behind-the-scenes AIS specialist SRT Marine Technology -- wrote to say he could astonish me if we could meet somewhere in Miami...and he did just that in the press room scene below. While Tucker isn't ready to go public with interesting new SRT hardware designs, consider the company's recent acquisition of GeoVS. Check out their real-time 3D vessel traffic visualisation system and understand that it can run astonishingly well on even a good laptop.



The just-out issue of Marine Electronics Journal has some interesting AIS bits -- -- particularly the wild Wave Gliders that may need transponders because they're getting run over:

Posted by: Ben at February 25, 2014 2:33 PM | Reply

Any idea when the Icom 504 will be available for sale (in the USA) or what the price will be? The Icom web site just states 'this product not yet available for sale' or something like that.

I will be buying a new VHF / AIS unit in the spring, either the SH 2150, Simrad RS35 or the Icom unit (if they sell it and the price is right). I also will buy a remote mic.

I want NMEA2000 to make integration easy.

I have a SH 2150 on my current boat and it works great but that boat is for sale and the VHF will go with it.


Posted by: Barry Lenoble at February 25, 2014 3:20 PM | Reply

Hi Barry, Icom can't sell it until it passes FCC approval, and that's why they're also reluctant to list prices. But I noted this in the original M506 entry:

"Pricing is not set but may look something like $500 for the base model plus a $100 each for the two major options plus $50 for the rear mic."

Posted by: Ben in reply to Barry Lenoble at February 25, 2014 3:38 PM | Reply

Hi Ben,

I look forward to your report on the Vesper XB8000. I have been impressed with the specs and based on Vespers reputation expect it to work well. Hopefully you can test it with a Garmin chartplotter, I have a 5212 in my boat.


Posted by: Howard at February 25, 2014 5:29 PM | Reply

As someone who considers himself relatively “techie”, I have to admit that I haven’t yet, after 8 years of ownership and some major open ocean cruises, gotten around to connecting my ICOM radios to my GPS. Not because I don’t want to, or haven’t tried. It is all about the physical difficulties of tracking down the necessary wiring to interface the legacy Raymarine electronics on the boat to the ICOM radios.

The Raymarine equipment speaks its own language (Seatalk) while the ICOM radios speak NMEA-0183, and there are other pieces of equipment with their own electrical demands, none of which want to play well with anything else. I think I have an NMEA-0183 output on my autopilot, and have tried to connect this, but it doesn’t seem to work. I don’t know if the autopilot is not talking, if the ICOM radios are not receiving, or if I am using the wrong wires.

In addition, the ICOM radios use connectors that are very strange: I seem to remember that they resemble co-ax, with very fine stranded wires that were quite difficult to connect to the 22ga wires that I think led to the autopilot.

What I am getting to in all this rambling is that the manufacturers have made no progress whatsoever in creating common, standardized interfaces that allow these pieces of equipment to be connected without a LOT of aggravation. I know there has been a LOT of talk on this web site about the new NMEA-2000 standards, but I also see that the manufacturers are creating their own sets of proprietary connectors for this network. There are wireless connections, but they are only proprietary. No one really wants to play with anyone else, for fear of losing a sale.

I am sufficiently techie that I am now in my third generation of laptop computer on this boat. I don’t have any problem spending money on tech, if it works and interfaces well, but there does not seem to be any visible hope that this will happen with marine electronics. And when it comes to connecting stuff on boats, it is a LOT harder than in houses, because the wiring is fussy and expensive and difficult to run, and no one wants to have to replace it. When you do succeed in replacing one wire, you inevitably disturb something else (electrical or plumbing or structure or fuel or female(the wife whose boat has been turned upside down)). And this leads to more troubleshooting and aggravation.

So what happens is that no one wants to disturb the stuff that is already installed and that works. No one wants to re-run wiring behind the panels, up the mast, under the berths, and thru lockers that have to be removed. We are willing to buy the stuff, but it is too hard to connect it together so we live with the old equipment and without all the nice bells and whistles that we would like to have. When the marine electronics manufacturers figure out how to address this aspect of the problem, then I think that they will find a LOT of new equipment sales from guys who like techie-stuff.

Posted by: rxc at February 25, 2014 8:01 PM | Reply

"What I am getting to in all this rambling is that the manufacturers have made no progress whatsoever in creating common, standardized interfaces that allow these pieces of equipment to be connected without a LOT of aggravation."

That's simply not true, RXC. NMEA 2000 really isn't new anymore and there's really only one non standard N2K connector these days. That's the Raymarine STng cabling system and adapter cables to regular N2K are readily available.

I've used VHF radios with NMEA 2000 interfaces from Garmin, Lowrance, and Simrad and only the latter (RS35) had difficulty using most any GPS on the N2K network (a glitch which Simrad rapidly fixed). More glitches are certainly possible but in general a VHF with an N2K port will get GPS easily. Then as long as the owner or installer inputs an MMSI, it's a fully operational DSC radio.

There are other ways besides for GPS that a DSC radio can use NMEA 2000 -- like plotting a boat in distress -- but I've rarely tested them because I hardly ever hear DSC calls of any sort. Kind of chicken and egg thing.

At any rate, here's a site that does a good job of explaining the various Raymarine data protocols. Note the discussion of several Seatalk to NMEA 0183 converters. I agree that the 0183 wires on many radios including Icom's are annoying but I bet your boat's Raymarine GPS could get to your Icom via a converter.

Posted by: Ben in reply to rxc at February 25, 2014 10:58 PM | Reply

I agree with rxc's sentiment. I do not understand why any wire less than 18ga is used for any of the connections.
There are still vendors who say they are NMEA2000 but have a proprietary cable such as connecting a Fusion i700 to NMEA2000.
Why would a NMEA2000 interface maker build a device to connect NMEA2000 to a computer but then not pass all of the NMEA traffic?
I can understand when new equipment cannot support some of the legacy features / functionality due to technology changes but when new equipment is being developed with proprietary cabling, that does not make sense.

Posted by: HenryD at February 25, 2014 11:35 PM | Reply

Henry, I'm not saying that NMEA 0183 isn't a pain, though there are certainly a lot of working 0183 connections on boats. What I am saying is that there has been progress; it's undeniable.

Sure, I suppose Fusion is THE other example of current non-standard N2K connectors, but it's a stereo for gosh sakes. And once you have the regular N2K adapter cables you'll never know there's oddball connectors in the mix. I wish Fusion had just gone standard but they certainly had a reason to do what they did, which is a cheaper self-powered network solution to use with their remotes on boats that don't have regular N2K.

Same for Maretron USB100, which I presume is the PC gateway you're unhappy with. It does pass all N2K traffic but only to Maretron's own software. It also translates some N2K messages into 0183 for the use of other software. Maretron could be clearer about what it does and doesn't do in its product description but remember that there still in no standard format for devlivering N2K data to applications outside CanBus. OneNet will change this.

Posted by: Ben in reply to HenryD at February 26, 2014 12:29 AM | Reply

Ben, I agree with most of everyone's comments about NMEA interfaces to VHF radios. They will all interface, many just have higher thresholds of installer pain and agony to do it. I have a VHF manufacturer's loaner programming box and special software I'm using to reprogram a VHF's radio. This will take virtually uninstalling the radio, re-connecting it to the programming box, wiping the number and reconnecting the radio back up. The alternative is pulling the radio, and sending it to the manufacturer for MMSI erasure. there will be a fee in either case. It's a lot of work to change a single number.

All boats eventually change ownership. Wouldn't it be a lot easier if an existing MMSI number could be moved to a new MMSI registration form in the data base. An existing MMSI number can be moved to a new boat, why can't it also be transferred to the new owner?

Posted by: Bill Bishop at February 26, 2014 7:34 AM | Reply

Hi Bill, An MMSI issued by BoatUS can be transferred. Here's the form:

I don't know if that's possible with an MMSI issued by the FCC and I also believe that you can not transfer a BoatUS MMSI# to the FCC if a boat is going outside U.S. waters and therefore requires an FCC issued number. Pretty messy.

But the radio manufacturers are only following ITU rules when they make radios (and AIS transponders) that can not easily have their prime MMSI number changed. It sounds like a wise security precaution -- hey, we don't want bad guys using fake identities -- but it doesn't really make sense. A bad guy can buy a new DSC VHF for little more than $100, program in a fake or spoofed MMSI, hook up a GPS or fake GPS feed, and he's all set. And ditto for a Class B AIS transponder, only for about $500 minimum and a lot harder to fake the GPS. Meanwhile, how much will your customer spend to a perfectly legitimate MMSI change?

Posted by: Ben at February 26, 2014 9:55 AM | Reply

I welcome the ease if interfacing that NMEA 2000 brings, but I fail to see what is so hard about interfacing a GPS and a VHF comm using NMEA 0183. I've done it a number of times in my boat and in friends' boats, with various different GPS/radio combinations. It's actually quite simple.

Posted by: Raul at February 26, 2014 10:44 AM | Reply

Many thanks Ben. BoatUS actually has two very similar looking MMSI FAQ pages. One talks about transferring MMSI numbers, the other one does not. I of course read the wrong set of FAQ's. This must be the same reason bread always ends up on the floor butter side down.

Posted by: Bill Bishop at February 26, 2014 10:57 AM | Reply

Raul if you have had some practice I agree with you, it isn't tragically difficult. But for someone (average boater) who isn't familiar with the jargon (A, B, RX, TX, +, -, talkers, listeners) and variances in wiring schemes (does this wire have to go to ships ground?) it might as well be magic. Add to this finding the MFD's NMEA harness under a console (often an odious task all by itself), figuring out what ports you can use, their wire colors (can the manual be found?), and then in some cases you may have to set/change the ports characteristics (more strange words like baud, and stop bits). Even with the zillion I have done,I always just twist the wires together, and check operation before doing a more permanent connections. I too can be briefly confused by instructions that are often written in the "Height of Brevity" style.

Posted by: Bill Bishop in reply to Raul at February 26, 2014 11:41 AM | Reply

I'm going to second the comments about NMEA-0183 being a major PITA - with N2K (or WiFi & Ethernet) any interface issues are software/programming dependent - is it speaking the same language, will the frames I need go thru? But with 0183, the actual, tiny, bizarrely-colored wires HAVE to match - a serious issue, especially when going between different brands. Yes, 0183 is fading into history, but unless you're buying all new (and sometimes even if you do!) you have to deal with it if you want things to work.

I bought all new everything (except depth/speed/wind) last summer and installed it - all Raymarine except the GX1600 VHF radio, because I really didn't want to replicate the problems I had with Raymarine chartplotter causing the Simrad autopilot to go dead if someone accidentally hit "go to".

I read the books for the VHF radio and the e95 several times, and I can tell you, it was a major Champagne moment when all of the 0183 connections worked! (Or appeared to work -- I still haven't verified that the DSC data is flowing from radio to MFD, but I expect to find out this summer..:-)

N2K simply doesn't concern me the same way - Raymarine explains the connector issues quite clearly (as does Panbo!) so if I want to hook up another brand of N2K device, I have every confidence it will work - but the same doesn't apply to NMEA-0183. If there is a good "all purpose/all brand NMEA-0183 interfacing" document out there, I haven't found it.

So we're all complaining about an obsolete standard that is for sure fading away, and no one is going to invest in making it work any better/easier, so what's the point? The point is: PLEASE start putting N2K interfaces in EVERYTHING on the market today! Stop fooling around with NMEA-0183 to meet regulatory requirements and just do it! Are there reasons why N2K to -0183 interfacing is so difficult or expensive it can't be done internally (or with a cheap/easy plug-in external box)?

Posted by: Hartley at February 26, 2014 12:45 PM | Reply

Hi Ben,

Good post. Dealing with marine electronics everyday you forget how difficult some people can find NMEA0183 and I was surprised that there are so many DSC Radios not being used as they were intended.

I had been intending to release some Tech Notes on how to wire some of our products to DSC radios and your post spurred me on to actually do it.

This afternoon, on our blog I have published the first one on Icom radios and I will publish another one tomorrow on Standard Horizon.

The new generation of radios with built-in GPS and NMEA2000 will make things easier, but people do not change their VHF radio very often and if we can help the people that already have a DSC radio to wire it up correctly, then it has to be a good thing.

All the best
CTO of Digital Yacht

Posted by: at February 26, 2014 1:22 PM | Reply

Thanks, Paul, that's an impressive document. I had no idea that Icom used that many NMEA 0183 wire schemes over the years. Also nice to see that M506 discussed above doesn't use the annoying co-ax 0183 wire and even has a useful 0183 connector (if you can find its match).

Between you and Nick Heyes (link above), Digital Yacht has become quite an information source. I spent some time in your blog and found lots of good stuff, like this app list:

Posted by: Ben in reply to at February 26, 2014 1:56 PM | Reply

I just corrected a mistake about the McMurdo M5 AIS. It only claims to be the first Class A to alarm on AIS MOB devices, and I should have known not to generalize that. Heck, I documented the way Vesper started displaying such devices before SART and MOB got distinguished:

Nowadays Vesper displays and transponders can even set off a relayed alarm for an AIS MOB alert without setting it off for a collision alert (if that's what you want).

Posted by: Ben at February 26, 2014 2:14 PM | Reply

Pretty good answers from Icom about AIS behavior:

* An M506 without the built-in AIS receivers will display (and presumably direct call) targets coming in over NMEA 2000 (but not over NMEA 0183).

* An M506 with the built-in AIS receiver and AIS input over N2K will display the latter.

Posted by: Ben at February 26, 2014 2:43 PM | Reply

Thanks Ben, always very interesting.

Curious if you or others here have heard of development of incorporating AIS Transponder, DSC, GPS in a handheld.

Would be very useful I think.

Posted by: Mark at February 26, 2014 3:14 PM | Reply

Hi Mark, I presume you mean an AIS MOB device combined with DSC VHF radio (GPS would have to be included with either)? But, sorry, I have not heard of such a combo and, as with combined AIS transponders and fixed VHF, I'm dubious that it's possible to satisfy all the regulatory hurtles.

Posted by: Ben in reply to Mark at February 26, 2014 4:02 PM | Reply

Paul, that's a great resource! Even though I don't have an Icom, I really appreciate the effort - and I'm looking forward to the succeeding editions..:-)

Posted by: Hartley in reply to at February 26, 2014 7:40 PM | Reply

Following on from the Icom Tech Note, here is a link to an article I have just published on Standard Horizon.

I think that covers the two leading VHF manufacturers, not sure if there is another manufacturer worth doing, as the customers that go for a complete system from Raymarine, Garmin, Navico or Furuno will pay more but supposedly benefit from simpler plug and play installation.

Posted by: at February 27, 2014 6:27 AM | Reply

Hi Ben, a wonderful website, full of great information. A question regarding class B AIS transponders?
I have bought an Australian GME AIST 120, transponder.
I have to mount it below decks in my aluminium sloop, and it is connected to my Raymarine A78 MFD(mounted above decks, so the internal gps will work ok), via a seatalk1 to seatalkNG converter with a devicenet connector. I have not yet installed the units.

GME tells me that I must connect an external GPS antenna directly to the AIS unit as it will not receive the GPS data via the seatalkNG network.
do you know any reason for this, do you have any experience of this problem? The AIS unit will happily broadcast the GPS data over the RaymarineNG network, but not receive it?
Cheers from Keith.

Posted by: keith at February 27, 2014 10:20 PM | Reply

GME is advising you correctly, Keith. Your transponder needs its own GPS because it uses it for precise communications timing as well as position. By regulation it will not broadcast unless its internal GPS has a valid fix, so you will need to install its external GPS antenna.

It's not an issue for you but the GPS in your transponder will have only limited use on your NMEA 2000 network. It's unnecessarily inherited from the limited bandwidth of NMEA 0183 AIS connections, I think, but transponders do not output a full set of GPS messages and they do not output the fast GPS positioning we're becoming used to. There's often some configuration of GPS output possible, but no matter how configured many MFDs will not recognize transponder output as valid GPS.

Posted by: Ben in reply to keith at February 28, 2014 7:12 AM | Reply

Howard (and Ben): Just an FYI: I have been reading with interest (more interest than usual, anyway) a current Cruisers' Forum thread in which Jeff Robbins of Vesper and one of his vendors are participating:

There's a lot of technical information there on the "Touch" and the 'black box' XB 8000 AIS that those interested in a Class B transponder would likely appreciate.

Posted by: Marc Dacey in reply to Howard at February 28, 2014 9:06 AM | Reply

Barry, I'm picking up a new SH GX2200 tomorrow for the same "boat show price" as my chandlery was selling the 2150 for. The 2200 features an onboard 66-channel GPS as well as the AIS and thereby reduces the number of external connections required. It's worth checking out, I believe, if you've enjoyed the 2150 you've already used.

I have to assume that if I can get it in frozen Toronto, it should be widely available as of the end of February.

Posted by: Marc Dacey in reply to Barry Lenoble at February 28, 2014 9:10 AM | Reply

Thanks, Marc, that is an interesting thread on the Cruiser's Forum. And it reminded me that Vesper may be the exception to what I wrote Keith about transponders not being able to supply GPS info over NMEA 2000. I'm part way through lab installing an XB-8000 and can see that it can send out more GPS info than any other transponder I recall, if configured to do so. I don't have a GPS antenna for it yet, but suspect it will be recognized as a valid GPS source by at least some MFDs. It's also an amazingly versatile Class B transponder, NMEA multiplexer, and WiFi gateway.

Posted by: Ben in reply to Marc Dacey at February 28, 2014 9:45 AM | Reply

Thanks for the link, it is good to see the manufacturer in direct discussions with customers. I really like the capabilities of the XB-8000.


Posted by: Howard in reply to Marc Dacey at March 1, 2014 5:44 PM | Reply

Ben, I'm curious about the ability of my Raymarine AIS650 to put it's GPS info onto the STng (N2K) buss in my (99% Raymarine) system. I had thought it didn't do it at all, but then discovered that my ST60 Speed instrument was still hearing SOG info, even when the e95 (the normal source of GPS info) was off (I have an ST - STng adapter installed for the olde Speed/Depth/Wind instruments). The e95 is between the STng network and my two DSC radios, so the 0183 ports are dead when it's off, and I can't tell what other info is there - but I figure if SOG is there, the rest probably is, too.
Now if my DSC radios interfaced to the N2K buss, they would work properly even with the MFD off!

Posted by: Hartley in reply to Ben at March 2, 2014 11:53 AM | Reply

Ben -

It seems your intended link that "does a good job of explaining the various Raymarine data protocols" was omitted.

I am one of those buyers that recently purchased an MFD on the basis (to some degree) of maintaining a single manufacturer system (Raymarine) in order to ensure simplicity of integration with legacy components….. not simple enough for me. Hopefully the link will help.

Posted by: Del in reply to Ben at March 2, 2014 12:19 PM | Reply

Not sure what Ben was referring to, but this page is pretty handy:

Posted by: Hartley at March 2, 2014 3:14 PM | Reply

Thanks, Hartley! That's the one.

Posted by: Ben in reply to Hartley at March 2, 2014 3:53 PM | Reply

That versatility is precisely why I think it will be perfect for my needs. Haven't decided if I want the associated Watchmate 670 display, however.

Having the AIS as a wireless router changes my plans significantly, actually. A lot less wiring, for instance.

Posted by: Marc Dacey in reply to Ben at March 4, 2014 5:01 PM | Reply

Thanks for the reply Ben. I now understand about the gps requirements for the class b ais transponder. I have ordered a dedicated gme gps external antenna to mount above decks.

Now, I have a raymarine devicenet A06045 female adaptor cable, that connects to the gme ais transponder. How can I get the data from the ais to show on the raymarine A78 MFD?

I have tried connecting the devicenet cable directly into the back of the A78 to the NG port and also through a seatlak1 to seatalk NG converter and also through a seatalkNG connector, but the A78 still shows no AIS?? Even though the A78 is configured to show AIS.

Does the AIS transponder only broadcast data over the nmea2000 port if it has a AIS target, or always transmit data? The diagnostics on the A78 show no sentences received over the NG port. The A
gme AIS is working properly as the green light is on and it has a clear view of the sky for it's internal GPS.

Can you please advise how to get the AIS data from the GMEAIST120 onto the NG bus or directly to the A78 MFD?

Cheers from Keith.

Posted by: keith in reply to Ben at March 4, 2014 8:04 PM | Reply

Hi Keith, I think you're almost there, but NMEA 2000 does not work one-to-one. It's meant to be a network and it MUST have its own power supply.

There are numerous good resources on N2K network designs, including one you can find in the "Networking/SeaTalkng" category in Ray's manual library:

Essentially you need a 5-port SeatalkNG tee or some similar combination of Tees and blue backbone cable. If you have the former a terminator (resistor) should go in each of the blue ports, making the tee the whole backbone. The adapter cable from the AIS goes to one white tee spur connection, the A78 to another, and 12v power (Ray makes a cable for that) to the third.

If you try that, or something similar, I believe you'll be in business. But you probably won't really know for sure until the AIS can see some targets.

Posted by: Ben at March 4, 2014 8:32 PM | Reply

Can we preorder the Icom m506? Any idea on release date?

Posted by: Luke at March 5, 2014 11:07 AM | Reply


I understand how you and many other people think that N2K is the great new connection standard that will let everyone connect everything to everything else. Unfortunately, I must disagree, in light of my experience connecting non-marine network equipment, and extrapolating that to the marine environment.

When I want to add a router or a bridge or a computer or a tablet to a wired Ethernet network, I just look at the performance specs and the price, and pick the one I want. I can find lots of patch cables (some of which are even reverse wired) that are available at a low price, and they all make the connections without my having to worry about the colors of the wires. I can even make up RJ-45 connectors myself, with tools that are really inexpensive, that work the first time I plug them in, so I can fish a cable without a connector thru a house without worrying about whether it will snag on something. The wires have been engineered to be able to run them thru ventilation plenums or on the outside of buildings (exposed to the rain and UV, etc). And there are already LOTS of IP67-rated connectors/covers being sold that go around the RJ45 connectors, to waterproof the connections to the equipment. Not at all expensive.

Why didn’t the equipment manufacturers take an existing, worldwide standard (Ethernet over twisted pair), and just put ports with RJ45 connectors, on their boxes, starting, say about 15 years ago, when computer networking exploded? Why don’t they do that now? Why isn’t there a standard, open, non-proprietary set of messages for various equipment to send, so that everyone can recognize speed from a GPS vs speed from a paddlewheel vs windspeed from a wind-sensor, and computers can connect to the network and use that data on laptop/tablet chartplotters? Why aren’t the sensors supplied a with short pigtails that can be connected to a longer wire, so that if the sensor dies or a newer, better one appears, you don’t have to snake 50 feet of wire thru the boat all over again? Routers and bridges are available for less than$30 that allow a dozen machine to talk to one another. Lots of them run on 12v power that is easily available on a boat. Why can’t we use that equipment to build boat networks?

I go back to my original premise – there are a lot of people who would like to connect their GPS to their radios, but the manufacturers will not settle on communication standards that will allow everyone to talk to everyone else, so those of us who don’t have the money to afford professional installation will continue to make-do with what we have till it dies and we are forced to upgrade. The non-marine electronic industry is making a fortune selling network-connectable hardware to every grandmother who wants a router/WiFi access point and a camera to talk to her grandchildren, but the marine industry won’t provide that capability to sailors whose safety could really benefit from it. It is really sad.
(end rant)

Posted by: rxc at March 5, 2014 9:22 PM | Reply

Luke, Icom can not even take preorders until the M506 is FCC approved. They're hoping the approval will come through later this month. If so the radios will be available for preorder in April with delivery in late April or early May. But that's all hypothetical. The M506 is not yet for sale; that's the law!

RXC, are you at all familiar with modern marine electronics? While they all use Ethernet protocols for radar, sonar, and inter-connectivity, the devices use different Ethernet connectors because there is no standard marine quality connector and you can't just plug a regular RJ45 jack into the back of an MFD or radar and expect it to hold up (the splicers you mention don't really matter).

NMEA OneNet will specify an existing, worldwide industrial Ethernet connector standard just like NMEA 2000 uses an existing, worldwide standard for connectors and cables (and is based on existing, worldwide CANbus protocol standard). Just because DeviceNet, CANbus, etc. are unfamiliar to many home and office networkers doesn't mean they aren't quite appropriate to boats.

In fact, a common trouble area on many boats these days is the conventional home and office routers being used to network communications, entertainment, and some Nav info. We may live and work on our boats but they are very different from homes and offices in terms of networking issues.

Finally, there's not one but two "standard, open, non-proprietary set of messages for various equipment to send, so that everyone can recognize speed from a GPS vs speed from a paddlewheel vs windspeed from a wind-sensor" -- NMEA 0183 and 2000. Just yesterday I was using a simulator to push GPS, boat speed, wind, and other data to all sorts of displays over an N2K network. No wire colors nor wire splices were involved. Most displays understood the standard messages fine. Why is this reality hard to grasp?

Maybe if you turned your own argument around it would help. Why aren't cars and trucks full of cheap RJ-45 connectors and Ethernet switches to handle all the sensors? Are your boat's critical navigation data networks more like a vehicle or a building?

Posted by: Ben in reply to Luke at March 6, 2014 10:54 AM | Reply

Thanks Ben. Hope to be able to preorder this radio soon.

Posted by: Luke in reply to Ben at March 6, 2014 11:34 AM | Reply


Where do I go to get a copy of the NMEA-0183 and N2K standard? I believe that if I want a copy I have to pay NMEA for it. Do all the manufacturers use that standard, without any "added proprietary features"? I think not.

Regarding Can bus, from the Wiki page on Can bus:

"... However, the mechanical aspects of the physical layer (connector type and number, colors, labels, pin-outs) have yet to be formally specified. As a result, an automotive ECU will typically have a particular—often custom—connector with various sorts of cables, of which two are the CAN bus lines. Nonetheless, several de facto standards for mechanical implementation have emerged, the most common being the 9-pin D-sub type male connector ...

"... The absence of a complete physical layer specification (mechanical in addition to electrical) freed the CAN bus specification from the constraints and complexity of physical implementation. However it left CAN bus implementations open to inter-interoperability issues due to mechanical incompatibility. ..."

I.e., there is no standard connector.

I did a quick search on waterproof RJ45 connectors, and found a whole bunch of them available on-line. And the marine environment inside a boat is really not that harsh - If you want to install a lot of stuff on a Boston Whaler or a dinghy, yes, it will get wet. But so do all the cables and routers and access points that companies like Ubiquity build and market for use outdoors. They seem to have no problem building a waterproof connection for their transponders that uses an RJ45 connector! And they don't charge an arm and a leg for them, either. Building waterproof moderately shockproof stuff is not that difficult. If you think that it has to meet a MilSpec standard for a sailboat, then you are overdesigning it.

Cars and trucks are more space-constrained than boats, and their manufacturers also like to keep their customers tethered to them for spare parts. Hardware for houses is not space-constrained. In anything bigger than a 22ft sailboat there is LOTS of space to hold one 12 port bridge router.

Finally I would ask, after all these years, why do we still have companies building stuff with Seatalk, Seatalk(ng), Seatalk2, Canbus, NMEA0183, N2K, Garmin net, Lowrance Net, Simrad net, Devicenet, etc? Why not one standard?

Your simulation comment says it all:

"Most displays understood the standard messages fine. "

Why didn't ALL the displays understand the "standard" messages"?

Posted by: rxc at March 6, 2014 9:31 PM | Reply

This is getting silly, rxc. You really need more than Google to argue successfully about this stuff.

* The NMEA 2000 standard, like very many other open standards, uses document fees to finance the standard making process. Folks who have only experienced recent Internet standards -- which were actually financed by government, universities, and large corporations -- tend to think that open means free. It doesn't. Open means open for anybody to use. NMEA standards are open.

* Both NMEA 0183 and 2000 permit proprietary messaging, though it has less network priority. It's good for innovation and you'll find the same feature in Ethernet, USB, and other protocols if you look.

* CANbus is mostly an underlying protocol for many "higher layer" implementations. You only had to look a little further on Wikipedia to learn that:

* DeviceNet, like NMEA 2000, is one of those higher implementations and it's also an open cable and connector standard for CANbus. Dozens of manufacturers make DeviceNet cables and connectors that you can use on your boat just like Garmin, Furuno, Navico, Maretron, etc N2K cables and connectors (many of which are relabeled DeviceNet gear). You can easily confirm this by searching eBay for DeviceNet micro and/or mini cable.

* But to my knowledge there is no standard for waterproof RJ45 connectors. The fact that there are "whole bunch of them available on-line" does make a standard. What we want to see in a standard connector is a whole bunch of manufacturers making the same connector to an appropriate specification. See DeviceNet/NMEA 2000 above.

* Your thoughts on vehicles versus buildings are simply fallacious. Failing connectors and cables are a prime source of electronics failures on boats. I don't want to go to sea with your standards.

* Why do we live our terrestrial lives with Ethernet, WiFi, USB, Bluetooth, Ant, etc. etc? Why not one standard? I'm only kidding; there are are excellent reasons for all those and many other networking standards. The real question is why are some people only comfortable with the few network standards they know a bit about?

* Finally, it's certainly true that NMEA 2000 is not quite a perfect multi-manufacturer standard. Just like Ethernet, USB, and Bluetooth were sometimes troublesome before years of adoption by zillions of users. Did you forget about all that, rxc?

Posted by: Ben in reply to rxc at March 6, 2014 10:39 PM | Reply

rxc, read your original comment again. You are a poster-boy for the problem NMEA2000 was designed to solve. Ditch the old equipment and buy new N2K stuff. It's great and it is simple to connect. Running new cables is never fun but you can start with a simple network and expand it later when you see how nice it is. For all the reasons why Ethernet is not (yet) used, see the Panbo archives.

Posted by: norse in reply to rxc at March 7, 2014 8:21 PM | Reply

". I've heard Coast Guard rescue center personnel report that a DSC alert can work beautifully to quickly identify and locate a boat in trouble "

Yes ...IF the Coast Guard would use it......which they do not do YET in the midwest on the Ohio river

Posted by: Anonymous at March 13, 2014 8:36 AM | Reply

True, but "Rescue 21 is operational along the entire Atlantic, Pacific and Gulf coasts of the continental United States as well as along the shores of the Great Lakes, Hawaii, Puerto Rico, the U.S. Virgin Islands, Guam, and the Northern Marianas Islands, covering approximately 41,871 miles of coastline."

Alaska and the Western Rivers got modified Rescue 21 systems, in the Rivers case without DSC coverage, detailed here:

Posted by: Ben in reply to Anonymous at March 13, 2014 8:44 AM | Reply

Got a frustrated note from a boater who has discovered that his new AMEC Camino-108 Class B transponder will NOT provide GPS info to his new ICOM 506 VHF (though it does provide AIS data fine).

This is not really a surprise to me because most transponders do not send complete GPS info, even over NMEA 2000. But the Vesper XB8000 and Vision transponders do, as demonstrated here:

AMEC could fix this with a software update, but everyone should be careful about presuming that transponder GPS can be used by networked navigation devices.

Posted by: Ben at June 17, 2014 8:03 AM | Reply


Even the SRT gen 2 based devices which are used by 90% of the OEMs don't do this 100% correctly. It sends out enough information over 0183, but over 2000 it does not send the precision of the fix, so that MFDs aren't able to select it automatically. It does send out enough data for it to be -selectable- as a GPS. 0183 doesn't have this issue of course, you never want more than one GPS on one NMEA stream, even if it is multiplexed.

My bet it will be 2020 before we see smooth operation between AIS transponder, VHF and MFD over NMEA 2000. GPS data, DSC point + click calling, all still pie in the sky stuff in 2014!

Posted by: Kees in reply to Ben at June 19, 2014 3:28 AM | Reply

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