# NMEA 0183 vs NMEA 2000



## Dean101 (Apr 26, 2011)

Ok, I'm a little confused by these. I'm 90% sure they are communication "languages" that allow different electronic devices communicate and share information with one another. I'm up to 99% sure that NMEA 2000 supercedes the 0183. Now for a few questions.

1. Does NMEA 2000 work with older 0183 devices?

2. How much longer will 0183 be good for?

3. Is there a significant performance difference or just a difference in how they are connected?

4. Is there a good source I can read to better understand NMEA and how different systems can be hooked together so it all works together with one display but can still operate independently in case of failure in a single device?

5. Am I the only person in the world who doesn't understand this stuff?

I'm not very electronicly inclined so speak very s l o w l y please!


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## Melrna (Apr 6, 2004)

Dean101 said:


> Ok, I'm a little confused by these. I'm 90% sure they are communication "languages" that allow different electronic devices communicate and share information with one another. I'm up to 99% sure that NMEA 2000 supercedes the 0183. Now for a few questions.
> 
> 1. Does NMEA 2000 work with older 0183 devices?
> Depends on the equipment installed. Most manufactures have dual or triple ways to connect. If they don't you can get a converter box. Most 1083 cannot read 2000. Raymarine uses their own system called Seatalk. Having said that though most instruments can read 1083 and few can read 2000,
> ...



Hope that helps.


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## BarryL (Aug 21, 2003)

Hey,

NMEA 0183 and 2000 are completely different. They are not 'languages' but really specify the electrical connection between two (or more) devices. NMEA 0183 is like serial communications that old computers used. NMEA 2000 is more like Ethernet networking.

The two are not interoperable at all.

Most DEVICES (plotters, radios, etc.) that can accept NMEA 2000 INPUT will also accept NMEA 0183, but this is because the device will have two or more communication powers.

NMEA 0183 is an old standard that has been around for a long time and will continue to be around for a long time. It is simple and cheap. It is designed so ONE piece of equipment (TALKER) to communicate to another piece of equipment (LISTENER). For example, a DSC VHF radio can obtain GPS location position from a GPS, or a wind speed and direction instrument can send information to a chart plotter with GPS speed so the plotter can calculate TRUE wind information. The information can only flow from one device to another device. You can't connect multiple devices NMEA 0183 device together unless you add additional gear (multiplexor). NMEA is SLOW (2400 baud typically) and requires you to connect little tiny wires.

NMEA 2000 is a newer standard that supports true networking. Think of computer networking where there can be multiple devices all communicating at the same time and to each other. With a NMEA 2000 network there is a network backbone (wire) that ALL devices connect too. You can have a GPS sending location information, water speed transducer sending speed through water information, wind instruments, AIS, Autopilot, etc. It is simple to add displays that allow you see whatever information you want. To add another NMEA device all you need to do is plug it in to the network and it starts working immediately.

Some additional tidbits:
Raymarine used to have a non-standard interface called SeaTalk. This is now obsolete as Raymarine has gone to SeaTalkNG (Next Generation) which is really just NMEA2000.

A good place to learn more about boat electronics is the Panbo Blog run by Ben Ellison. Visit it here:
Panbo: The Marine Electronics Weblog

My own opinion is that if you just want a simple system, say chart plotter with GPS connected to DSC VHF radio, then NMEA 0183 is fine. If you want something more involved, say you want an autopilot that can get information from the plotter, and you want to add wind and boat speed through water as well, you are better off with NMEA 2000.

Barry


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## Dean101 (Apr 26, 2011)

Thanks for the responses. Very informative. I've read in a few threads here that people have put together what sounds to me like pretty elaborate navigation and monitoring networks. 

I don't have enough experience to know exactly what type of electronics I would actually need for what I intend to do but I'm sure I will go for a chartplotter and radio at the minimum. Since I will be mostly singlehanding, AIS strikes me as a useful tool, and possibly a simple radar package. 

It seems to me that having information from all devices available at the helm as well as a good monitoring system for engine status would be pretty handy for those times when I would need to remain on deck. I like the idea of being able to display and manipulate everything from a single MFD rather than having a huge spread of instruments in front of me complete with airbag!


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## svzephyr44 (Jun 26, 2000)

BarryL said:


> You can't connect multiple devices NMEA 0183 device together unless you add additional gear (multiplexor). NMEA is SLOW (2400 baud typically) and requires you to connect little tiny wires.
> Barry


Barry's information is mostly correct. NMEA 0183 was defined in 1983 (wow.) It operates at 4800 baud, eight bits, one stop bit, no parity. Except for high speed NMEA which is used only for AIS connections.

A NMEA Talker can power 4 NMEA listeners. A NMEA listener can only listen to one talker.

The big problem with 0183 is that people like Raymarine decided to violate the standard that says anything a listener hears needs to be repeated on the talker side of the instrument. They did this so they could sell expensive and unnecessary "conversion" boxes.

As pointed out above NMEA 2000 is the new standard. Usually manufacturers don't repeat NMEA 2000 data onto NMEA 0183 outputs. What does this mean. Well, lets say you purchase a NMEA 2000 wind instrument but have a NMEA 0183 multi-function display. Guess what, the NMEA 2000 wind data will not show up on the NMEA 0183 multi-function display. They do, however, usually repeat NMEA 0183 data on the NMEA 2000 bus. So if you buy a NMEA 0183 wind instrument and a NMEA 2000 multi-function display the wind data might show up on the the multi-function display. Confused yet?

Simple rule. If you have old instruments that communicate on NMEA 0183 you probably want to get new instruments that will talk NMEA 0183. If you are getting new instruments then go with NMEA 2000.

BTW most chart plotters talk both, but again the rub is what the rest of your instruments will display. The good news is that the tech support people at Garmin etc. are pretty good about telling you what will happen if you call them up and say "I have these specific instruments wired together like this."

Last comment to make it even more confusing: Back in the dark ages (yesterday) all of the manufacturers had proprietary communication protocols - Raymarine had SeaTalk, SeaTalk2, HSI, and a couple of others. None of these talk to NMEA 0183 or NMEA 2000 without a converter box.

You may start drinking heavily now. 

Fair winds and following seas.


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## Dean101 (Apr 26, 2011)

Yes, I think a stiff drink is in order!:hammer


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## Iliana (May 22, 2014)

Hi all,
I read the answer of svzephyr44 and I would like to ask sth similar.
I have a ship, which has NMEA 0183 protocol in the bridge systems. And another vessel with NMEA2000. Should I use a different NMEA reader (0183 and 2000 respectively) for every case, or I can use the same?
What should I look into, in order to be sure that I will be compatible?
Any product suggestions?
Thanks



svzephyr44 said:


> Barry's information is mostly correct. NMEA 0183 was defined in 1983 (wow.) It operates at 4800 baud, eight bits, one stop bit, no parity. Except for high speed NMEA which is used only for AIS connections.
> 
> A NMEA Talker can power 4 NMEA listeners. A NMEA listener can only listen to one talker.
> 
> ...


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## eherlihy (Jan 2, 2007)

I could write a book in an attempt to answer the original post... 
Short answer: NMEA 0183 and NMEA 2000 are _Protocols_, much like EIA 422 and Ethernet are protocols. And, there is a follow on protocol called NEMA OneNet. They are each run over different media, and at different rates. NMEA 2000 is based on the automotive CAN Bus, which has been used extensively in every vehicle built since the mid '90s (controls: fuel injection, instrument gauges, and more functions). You CAN buy NMEA 0183 to 2000 gateways.

You can read the NMEA 0183 standard here; NMEA

And, you can read the NMEA 2000 standard here: NMEA

Finally, you can read about OneNet here; http://www.nmea.org/Assets/20130628%20onenet%20summary.pdf


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## MarkSF (Feb 21, 2011)

I have an NMEA 2000 network with a Lowrance HDS 5 chartplotter, Garmin/Airmar DST800 sensor, Garmin GMI 10 display, and Simrad wind instrument. 

The Simrad is Simnet, which is NMEA 2000 but with a proprietary cabling system. I think Seatalk NG is the same deal. They are actually both major improvements when it comes to ease and flexibility of cabling. The Simnet and NMEA2000 co-exist just fine (Simnet network is plugged into the NMEA 2000 backplane)

Is is indeed very easy to share info. For example, when I added the wind instrument it immediately recognised and used the heading and speed data to calculate true wind.

I did run into one "gotcha" : some manufacturers use proprietary calibrations, which may not be supported by others. For example, the Lowrance does not have a calibration for the speed paddle. I had to add the Garmin GMI 10 so I could calibrate it. Conclusion : be careful when mixing manufacturers.


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## SVAuspicious (Oct 31, 2006)

VHF radio manufacturers have been slow to implement NMEA 2000. Almost all still use NMEA 0183.


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## Missingyou (Aug 16, 2013)

I've been struggling to understand it also but with my limited laymen's knowledge I liken the difference to an old school Serial port on my PC versus USB (without Device Drivers). I don't know if I would go as far as comparing NMEA 2000 to ethernet. 

My boat has Simrad, their implementation of NMEA 2000 is Simnet, which I like. Expansion is simple with hubs. No backbone with terminators or 'T's'. Connecting NMEA 0183 devices is via a simple AT10 adapter. My VHF(RS25) and AIS-B (NAIS300) are NMEA 0183. The newer NAIS400 from Simrad is Simnet. Downward compatibility with NMEA 0183 is really a non issue. 

As for connecting non Simnet devices it requires a cable with a Simnet connector on one end and a NMEA 2000 connector on the other. 

My complaint with NMEA 2000? It is in a sense a closed standard, you have to buy rights and the information to use it. No doubt because those who funded the development want to recoup their costs versus the industry big boys just having agreed to pony up and pay to develop an open standard. You or I for example can not easily go online and research the information necessary to develop a device to talk to NMEA 2000. Although this closed platform may help with the consistency, the quality of implementation, and the funding of the Standard, I think it has also limited the number of third part vendors making devices. This increases cost, but more importantly the choices to the customer.


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## eherlihy (Jan 2, 2007)

Missingyou said:


> I've been struggling to understand it also but with my limited laymen's knowledge I liken the difference to an old school Serial port on my PC versus USB (without Device Drivers). I don't know if I would go as far as comparing NMEA 2000 to ethernet.


My point was that NMEA 0183 is a physical, link, and transport layer communication protocol based on EIA 422, like the serial port, except that it allows one "talker" and multiple "listeners". This could not be considered a "network."

NMEA 2000 is a message based physical, link, network, transport, session, and presentation layer based protocol based on the Control Area Network (CAN) Bus. Because it is a network based protocol, it has the ability to interface to multiple (up to 50) "devices." Devices in this context can be either talkers or listeners, or both.

OneNet is a marine adaptation of the IEEE 802.3 or, as it is more commonly known, "Ethernet" standard.


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## Alex W (Nov 1, 2012)

Missingyou said:


> My complaint with NMEA 2000? It is in a sense a closed standard, you have to buy rights and the information to use it.


The same is true of NMEA 0183.

However there is enough information out there about both to develop devices that use either. NMEA 0183 is a little bit easier to work with, but not considerably easier.

NMEA 2000 has so many advantages that I could not see installing a new NMEA 0183 "network" today. The advantages that you'll see as an end user are more frequent updates from your devices. As an installer you'll see much simpler and more durable wiring.


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## goboatingnow (Oct 10, 2008)

0183 is correctly a protocol running on a conventional RS 422 physical link

2000 is both a message protocol and a serious is link and physical standards, it is a true network architecture 

The primary reason it's closed its an attempt ( incorrect in my view ) to enforce interoperability. Many systems like z-wave etc are also closed. 

Opener is a protocol for bridging NMEA 2000 out onto IP networks.


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## fallard (Nov 30, 2009)

I ran into a problem with my 10-yr old Raymarine chartplotter/fishfinder when my Raymarine 120 GPS (no longer available) got tired. That chartplotter was connected to the old GPS receiver with the old Seatalk, but the new Raymarine GPS 130 used Seatalk ng and would have required a ~$90 converter to go from Seatalk to Seatalk ng. 

The affordable solution to restore my position fix was to use a Digital Yacht GPS and connect it to the NMEA 0183 wiring built into the Raymarine chartplotter power cable. This was a $150 (Defender) solution vs. a $400 solution using the Raymarine GPS and Seatalk converter.


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## SVAuspicious (Oct 31, 2006)

Dean101 said:


> 1. Does NMEA 2000 work with older 0183 devices?


With conversion somewhere, either built into some other electronics or in a conversion box.



Dean101 said:


> 2. How much longer will 0183 be good for?


Until VHF manufacturers either decide to start paying the fees for NMEA 2000 (which are steep when you are trying to hit a $200 price point for your product) or hardware is available to pass GPS locations to DSC-enabled VHF radios using Bluetooth or something else.



Dean101 said:


> 3. Is there a significant performance difference or just a difference in how they are connected?


There is a significant difference. NMEA 2000 is much faster and allows multiple "talkers" on the same network segment. NMEA 0183 on the other hand is dead simple.



fallard said:


> I ran into a problem with my 10-yr old Raymarine chartplotter/fishfinder when my Raymarine 120 GPS (no longer available) got tired. That chartplotter was connected to the old GPS receiver with the old Seatalk, but the new Raymarine GPS 130 used Seatalk ng and would have required a ~$90 converter to go from Seatalk to Seatalk ng.


There are two related issues your solution addresses.

First, many chartplotters and autopilots have dedicated interfaces for NMEA 0183. Many, especially autopilots, are limited to 4800 bps so they aren't useful for AIS but for other data those interfaces solve a lot of problems without extra conversion boxes.

Second, at some point we'll all have to face the conversion from 0183 (or SeaTalk 1) to 2000 (or SeaTalk ng). Sometimes it is better to bite the bullet and take the first step into the future. We all have to make the choice ourselves on when that time has come. For myself, I'm still using NMEA 0183, SeaTalk 1, and SeaTalk hs. I suspect the next major electronics addition or replacement will push me to either a NMEA 2000 or SeaTalk ng backbone. I have some pretty complicated "stuff" on my boat, including serial to Ethernet conversion, that are going to make that painful. Oh well.


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## Alex W (Nov 1, 2012)

Simrad makes a AIS-rx/DSC radio that is NMEA 2000 called the RS35.

I bought it when first released and it was really buggy at the start, but with the latest firmware (which is now about 8 months old) it is a pretty nice unit. My only complaint is that you can't select which channels to scan, it either scans all of them or 16+9+oneMore. Scan is really fast and keeps one tuner locked on 16 (the radio has 4 tuners internally, 2 for AIS and two for audible channels), but the scan feature is useless in Canada which always broadcasts weather on 22.

It has no problems talking to my Raymarine e7d (after the firmware update) over NMEA 2000.


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## SVAuspicious (Oct 31, 2006)

Alex W said:


> Simrad makes a AIS-rx/DSC radio that is NMEA 2000 called the RS35.


Cool. Thanks for the heads up. Dual AIS receivers is impressive also.


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## knuterikt (Aug 7, 2006)

SVAuspicious said:


> VHF radio manufacturers have been slow to implement NMEA 2000. Almost all still use NMEA 0183.


Isn't this an old truth now?
Navico (Lowrance, Simrad and B&G)
Icom
Garmin
And probably more all have models with NMEA 2000 today.

Found this article The Latest in VHF Radios


> "There have been a lot of NMEA 2000 devices over the last five years, but VHF has been quite slow to have NMEA 2000 integrated," says Mark Harnett, regional sales manager and product manager for communications, safety, and AIS for Navico, parent company to Simrad (Simrad Marine Electronics) and Lowrance (LOWRANCE | Marine Electronics), among others. "We heard from users trying to integrate their DSC radio into their chartplotter for the DSC functionality to work and for any DSC calls received to be plotted on the chartplotter." Connecting the DSC radio to a GPS is required to get the full safety benefit of the system, yet end users have struggled with it-notably because there is no standard color for the wires that make the connection. NMEA 2000 is a protocol that uses a single standard connector to share data throughout the boat along a single backbone.
> 
> "We thought adding NMEA 2000 was going to make it much much easier for your average joe to connect DSC to his multifunction display," Harnett says. "It's just plug-and-play now-much simpler for connections."


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## knuterikt (Aug 7, 2006)

SVAuspicious said:


> Cool. Thanks for the heads up. Dual AIS receivers is impressive also.


Can you find any AIS receivers today that are not dual channel?

A class B transponder in a boat with SOG > 2 knots will be updated like this
Single channel AIS receiver every 60 seconds
Dual channel AIS receiver every 30 seconds

A class B transponder in a boat with SOG < 2 knots would be 6 min vs 3 min

These are the worst numbers
AIS class A have more frequent transmissions so better, but still x 2 for single channel receiver.

A god text on AIS here: http://www.digitalyacht.co.uk/files/Non Idiots Guide to AIS for the BMEA.pdf


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## Alex W (Nov 1, 2012)

knuterikt said:


> Isn't this an old truth now?
> Standard Horizon
> Navico (Lowrance, Simrad and B&G)
> Icom
> Garmin


Standard Horizon still doesn't have a AIS VHF receiver with NMEA 2000. The newest model, the GX2200, has built in GPS but not NMEA 2000.

I hadn't noticed the Icom unit (IC-M506 AIS), that looks like a nice radio. I wish that it had a wireless remote handset like the Simrad. I'd trust Icom to make a better VHF unit than Garmin or Simrad.

I wonder how long it will be before we can get an integrated VHF + AIS-rx-tx unit.


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## knuterikt (Aug 7, 2006)

SVAuspicious said:


> First, many chartplotters and autopilots have dedicated interfaces for NMEA 0183. Many, especially autopilots, are limited to 4800 bps so they aren't useful for AIS but for other data those interfaces solve a lot of problems without extra conversion boxes.


If you have an old chartplotter with only NMEA 0183 with 4800 bps it wont support AIS anyway.
My Furuno NN3D came with 
one NMEA 2000 port (you only need one)
two NMEA 0183 4800 bps
one NMEA 0183-HS 38.4K-baud or 4800 bps (configurable)
But it does only support AIS over the NMEA 0183-HS (NOT NMEA 2000 since AIS was not part of N2K when the unit was designed, and even with new SW versions it's still not supported.

My AIS class B transponder (em-trak b100) can send AIS data both on NMEA 2000 and on NMEA 0183-HS, it also have a NMEA 0183 port it can take the input on NMEA 0183 4800 bps and send it out on the NMEA 0183-HS togehter with the AIS data.



SVAuspicious said:


> Second, at some point we'll all have to face the conversion from 0183 (or SeaTalk 1) to 2000 (or SeaTalk ng). Sometimes it is better to bite the bullet and take the first step into the future. We all have to make the choice ourselves on when that time has come. For myself, I'm still using NMEA 0183, SeaTalk 1, and SeaTalk hs. I suspect the next major electronics addition or replacement will push me to either a NMEA 2000 or SeaTalk ng backbone. I have some pretty complicated "stuff" on my boat, including serial to Ethernet conversion, that are going to make that painful. Oh well.


A little research & planning make it possible to phase in new NMEA 2000 equipment and keep older stuff.
I have one converter between the MNEA 2000 backbone and my autopilot.
Luckily most new electronics use NMEA 2000 (SeatalkNG and Simnet) are also NMEA 2000 even though the have their own plugs and cabling.
No converters only different plugs 

I have NMEA 2000 equipment from 4 vendors
Furuno 
- NN3D MFD aka Chartplotter
Raymarine 
- wind/speed/depth/water temp old transducers 
- i70 displays and a ITC-5 to translate data from the old transucers
Em-trak
-AIS class B with both NMEA 2000 & NMEA 0183
Actisens
-NGW-1 NMEA 2000® Gateway to interface the Autopilot
-NGT-1-USB To interface with a laptop

The NN3D MFD use Ethernet to connect to the radar,
We found out that it the MFD transmits all data from N2K & NMEA 0183 out on the Ethernet, so it's possible to get that to the PC this way also.

One thing that is important to know if you start mixing different vendors is that configuration/calibration/software update is not a part of the NMEA 2000 standard.
So if you have Garmin NMEA 2000 wind sensor you need a Garmin display to calibrate the sensor.

Still have a GPS, DSC VHF and autopilot with NMEA 0183


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## knuterikt (Aug 7, 2006)

Alex W said:


> I wonder how long it will be before we can get an integrated VHF + AIS-rx-tx unit.


Don't think you will get that.
AIS tx will block your radio every 30 second, and you would block reception while you talk.

It's possible to build but you would need two antennas one for VHF and one for AIS.


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## knuterikt (Aug 7, 2006)

Alex W said:


> Standard Horizon still doesn't have a AIS VHF receiver with NMEA 2000. The newest model, the GX2200, has built in GPS but not NMEA 2000..


I will correct my post, thanks


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## SVAuspicious (Oct 31, 2006)

knuterikt said:


> Isn't this an old truth now?
> Navico (Lowrance, Simrad and B&G)
> Icom
> Garmin
> And probably more all have models with NMEA 2000 today.


NMEA 2000 is coming in VHF radios, but it has been very slow. A number have built-in GPS radios specifically to make installation easier and to avoid the costs to NMEA to license 2000.



knuterikt said:


> Can you find any AIS receivers today that are not dual channel?


Dual channel doesn't mean dual receiver. Some implementations simply scan back and forth between the two AIS channels with a single receiver. Again, the advent of multi-part chips is making those solutions less expensive.



knuterikt said:


> If you have an old chartplotter with only NMEA 0183 with 4800 bps it wont support AIS anyway.


I was trying not to ramble on at length.

Most chartplotters that support NMEA 0183 (all that I have touched lately) will support 38400. Some of the newer chartplotters (like the Raymarine a Series) don't support NMEA 0183 at all. Many autopilots have NMEA 0183 ports that are fixed at 4800 bps. They make nice bridges to get GPS to VHF radios for DSC but not for AIS. That discrimination was what I was trying to communicate.



knuterikt said:


> A little research & planning make it possible to phase in new NMEA 2000 equipment and keep older stuff.


Agreed, and my point. It is non-trivial however.



knuterikt said:


> Actisens


Actisense seems to have pretty well displaced Brookhouse in providing multiplexors and converters. Good equipment.



knuterikt said:


> Don't think you will get that.
> AIS tx will block your radio every 30 second, and you would block reception while you talk.
> 
> It's possible to build but you would need two antennas one for VHF and one for AIS.


Of course it can be done, just like current installations often use splitters to share a single VHF antenna. That doesn't make it a good idea. I think splitters are a bad choice and that separate VHF antennas for AIS and marine VHF is the much better solution. None of that means an integrated VHF/DSC/AIS isn't possible and even practical. It's all about a manufacturer deciding there is a market. There is no technical impediment.


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## goboatingnow (Oct 10, 2008)

> Of course it can be done, just like current installations often use splitters to share a single VHF antenna. That doesn't make it a good idea. I think splitters are a bad choice and that separate VHF antennas for AIS and marine VHF is the much better solution. None of that means an integrated VHF/DSC/AIS isn't possible and even practical. It's all about a manufacturer deciding there is a market. There is no technical impediment.


I agree I think we will see combined units very soon, maybe towards the end of this year. Right now theres a lot of AIS units with combined splitters and this makes the units very easy to install and provides the optimum performance. Most of the time the VHF radio on the mast top is doing nothing anyway

dave


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## Dean101 (Apr 26, 2011)

This has been a great discussion on this topic. Thank you all for the input!

It's been a couple of years now since I originally posted these questions and I think now I can add a little realistic context to my original post. This is how I see things playing out in the near future:

I will be buying a used boat as budget will be a big factor. At the price points I'm looking at any electronics are likely to be dated/worn out/non-functional. As I will spend a few years slowly refitting the boat to suit me and getting her ready to do some distance cruising, the electronics package will be something I will be overhauling. During this refitting period the boat will likely be located on the inland waterways around Kentucky. I honestly don't see myself investing in a lot of electronics at that point. A dependable VHF radio, a chartplotter, and possibly wind instruments at that point would suit me.

The second part of my cruising plan involves moving to the coast for coastal cruising and ocean experience while saving for an extended cruise. I've never done that sort of thing so I don't know what type of electronics I may need or want. AIS and possibly a radar package? Possibly. When I start venturing further afield I might even want an SSB set. I don't know at this point. 

So with that in mind and from what I can understand of your comments, would I be correct in thinking that NMEA 2000 would be the best for my needs as I will most likely start with a new, basic setup with the ability to easily add new units in a plug and play fashion to the initial package as desired? I should add that I want to be able to install all of this myself so I'm hoping I wont need an electronics degree in order to do it.


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## SVAuspicious (Oct 31, 2006)

goboatingnow said:


> Right now theres a lot of AIS units with combined splitters and this makes the units very easy to install and provides the optimum performance.


I'll agree with you on the ease of installation but splitters lead to far from optimum systems. 2.5 - 3 dB signal loss on both receive and transmit for both the AIS and VHF is not optimum. 3 dB is _half the power_. It is so easy to add a second antenna on the pushpit, radar pole, arch, or a spreader. Do that.



Dean101 said:


> A dependable VHF radio, a chartplotter, and possibly wind instruments at that point would suit me.
> 
> The second part of my cruising plan involves moving to the coast for coastal cruising and ocean experience while saving for an extended cruise. I've never done that sort of thing so I don't know what type of electronics I may need or want. AIS and possibly a radar package? Possibly. When I start venturing further afield I might even want an SSB set. I don't know at this point.


I would suggest you add an autopilot to the top of your coastal cruising list.

Electronics change quickly, and the next generation after NMEA 2000 is kicking around now. Just as there are converters available now there will be some for the next generation.

If you are starting from scratch, get NMEA 2000 or SeaTalk ng today and don't buy anything too far in advance for functionality you don't need yet.


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## Dean101 (Apr 26, 2011)

I'm still a couple of years from the purchase/refit stage. I should have mentioned the autopilot. That is one of my must haves along with a windvane eventually. That's good advice about not getting ahead of myself. I don't feel I have the practical experience with the various systems available to decide exactly what I may or may not need.


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## fallard (Nov 30, 2009)

Dean101 said:


> TAs
> The second part of my cruising plan involves moving to the coast for coastal cruising and ocean experience while saving for an extended cruise. I've never done that sort of thing so I don't know what type of electronics I may need or want. AIS and possibly a radar package? Possibly. When I start venturing further afield I might even want an SSB set. I don't know at this point.


IMHO you need to consider radar compatibility for your chartplotter. AIS would be a secondary consideration because there will be a lot of smaller vessels that don't have AIS and won't have it for the foreseeable future. When you get caught in a fog, you will want a better idea of who else is out there and radar is your best bet. AIS would be more useful when you are dealing with larger commercial traffic, but that is probably a small percentage of the time.

If you have radar with MARPA (Mini Automatic Radar Plotting Aid), you can tag a radar contact and have your radar calculate its speed and course and alert you to a collision hazard. MARPA requires user interaction, but you need to be actively aware of your situation in a fog, anyway. My basic Raymarine radar has MARPA and I would guess that most other brands may have MARPA as well, but you might check on this when you are researching chartplotters and compatible radars.

BTW, it is my understanding that SSB is only legal when you are out of VHF range. I gave mine up years ago, after using it only during a single 3 day offshore passage 18 years ago. I rarely--if ever--have been out of VHF range since then on my coastal cruising from Connecticut to Maine. When you are ready to go offshore, or maybe down the Bahamas chain, it may make sense, but you can sort this out when the time comes.


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## SVAuspicious (Oct 31, 2006)

fallard said:


> BTW, it is my understanding that SSB is only legal when you are out of VHF range.


Not true.

An SSB only requires a license. The US VHF license waiver does not apply to an SSB. Of course the VHF is supposed to be licensed anyway if you leave the coastal US or communicate with foreign flag vessels.

Properly licensed, a marine SSB may be used anywhere.


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## fallard (Nov 30, 2009)

SVAuspicious said:


> Not true.
> 
> An SSB only requires a license. The US VHF license waiver does not apply to an SSB. Of course the VHF is supposed to be licensed anyway if you leave the coastal US or communicate with foreign flag vessels.
> 
> Properly licensed, a marine SSB may be used anywhere.


Currently the US Coast Guard requires a VHF radio before you can install a SSB. As of January 1972, the FCC did not permit SSB transmissions to shore stations or vessels within VHF range. I haven't seen a revision to that rule, but even if it has been relaxed, the Coast Guard advises the use of VHF for shorter distance communications.

Perhaps SV can cite an FCC revision to the earlier SSB rule.


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## SVAuspicious (Oct 31, 2006)

fallard said:


> Currently the US Coast Guard requires a VHF radio before you can install a SSB. As of January 1972, the FCC did not permit SSB transmissions to shore stations or vessels within VHF range. I haven't seen a revision to that rule, but even if it has been relaxed, the Coast Guard advises the use of VHF for shorter distance communications.
> 
> Perhaps SV can cite an FCC revision to the earlier SSB rule.


My apologies for contributing to thread drift.

To my knowledge there is no requirement to have a VHF radio at all for non-commercial boats below 20 meters in length, called "voluntarily equipped" vessels. If a rule exists that I'm not familiar with and can be cited I'll be more than happy to research the history of changes.

I have never heard of any proscription on the use of HF/SSB radio beyond proper licensure.

Perhaps you are confusing the the carriage requirements for GMDSS Sea Area A1. Those are carriage requirements and not operational limits and don't apply to voluntarily equipped vessels.

Though somewhat dated due to the termination of USCG MF coverage the following is relevant: http://www.navcen.uscg.gov/pdf/gmdss/taskforce/gmdss_and_the_recreational_boater.pdf .

You may note that the FCC form 605 for a ships station license ( http://transition.fcc.gov/Forms/Form605/605b.pdf section 18 ) does not indicate any requirement for VHF over or before MF or HF (conventionally referred to as SSB by recreational boaters).

Note that there is no carriage requirement stemming from the license so it is worth ticking all the boxes when applying for a ships station license.

In the context of voluntarily equipped vessels--clearly the SailNet constituency--you can carry or not whatever communications you like. If you do carry a VHF on a voluntary basis there are watchkeeping ("monitoring") requirements (often honored in the breach).

There is a good deal of HF/SSB communication within Sea Area A1 (by definition in VHF range). The USCG participates. FCC-licensed coast stations get a good bit of attention. Monitored licensees like Sailmail and Chris Parker shore stations regularly communicate with ship stations (both voluntarily equipped and those subject to GMDSS carriage requirements).

In short, I fear you are misinformed. If you can cite specific FCC or USCG requirements you believe apply I'll be happy to address them. Anything I don't know or can't support I can get help with from colleagues.


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## fallard (Nov 30, 2009)

SVAuspicious said:


> My apologies for contributing to thread drift.
> 
> To my knowledge there is no requirement to have a VHF radio at all for non-commercial boats below 20 meters in length, called "voluntarily equipped" vessels. If a rule exists that I'm not familiar with and can be cited I'll be more than happy to research the history of changes.
> 
> ...


Certain vessels are not required to have VHF--we can agree on that. But we disagree that you can have SSB in US waters without having VHF. I have seen multiple references, including the USCG navigation website that say so. Form 605 is about licensing--not operational restrictions. My guess is that your license application will be rejected if you list SSB without having VHF. That said, it's hard to take the license application process seriously when everyone advises you to list everything you could possible put on your boat--whether you ever install it or not.

I will agree that SSB can be used legitimately in close, but not for functions that can normally be handled by VHF. When in extremis, we can all agree that you do what you have to do and apologize later, if necessary.

It has been 14 years since I had SSB, so maybe I haven't been paying attention to rules changes, but I still haven't seen where the FCC January 1972 rule proscribing SSB transmission when VHF is available has been superceded. I've looked, but searching the FCC website for information on this topic has not been easy.


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## SVAuspicious (Oct 31, 2006)

fallard said:


> Certain vessels are not required to have VHF--we can agree on that. But we disagree that you can have SSB in US waters without having VHF. I have seen multiple references, including the USCG navigation website that say so.
> 
> <snip>
> 
> ...


I would value a specific citation whether a link to an official web site or a CFR section. You said before you have seen multiple references. Please share.

Again - I have never seen a regulation that says one band (VHF) is to be used over another (MF/HF).

Finally I haven't seen the FCC Jan 72 rule you refer to at all. Please provide a citation.

There is an FCC representative on a USCG Task Force I sit on. If you give me something to work with I'll follow up.


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## fallard (Nov 30, 2009)

SVAuspicious said:


> I would value a specific citation whether a link to an official web site or a CFR section. You said before you have seen multiple references. Please share.
> 
> Again - I have never seen a regulation that says one band (VHF) is to be used over another (MF/HF).
> 
> ...


I haven't found the government source document, but the Gordon West intro to SSB (http://www.kp44.org/ftp/WestIntroToSSB.pdf) states, "Radio rules require that you must have a marine VHF radio in your vessel before you can install a marine SSB transceiver." You can also see Don Casey's quote, "The lowly VHF radio remains the most versatile communication device for a boat. It is the only communication device many pleasure boats are equipped with, and it is required by law before you can put any other marine radio aboard." (BoatUS - BoatTech - VHF Basics by Don Casey).

Regarding the use of one band over another, go to eCFR ? Code of Federal Regulations to see Title 47: Telecommunication, Part 80--Stations in the Maritime Services, specifically:

"§80.367 General uses-radiotelephony.
.
.
(f) Ship and coast stations authorized to use frequencies in both the 2000-27500 kHz and 156-162 MHz bands must not use frequencies in the 2000-27500 kHz band for communications with any other station which is within the VHF service range." (Note: 2000 - 27500 kHz is the marine MF-HF SSB "band")

Bottom line: if you've got SSB and are legal, you also have VHF and are obligated to use it instead of SSB when in VHF range.


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## SVAuspicious (Oct 31, 2006)

fallard said:


> I haven't found the government source document, but the Gordon West intro to SSB (http://www.kp44.org/ftp/WestIntroToSSB.pdf) states, "Radio rules require that you must have a marine VHF radio in your vessel before you can install a marine SSB transceiver." You can also see Don Casey's quote, "The lowly VHF radio remains the most versatile communication device for a boat. It is the only communication device many pleasure boats are equipped with, and it is required by law before you can put any other marine radio aboard." (BoatUS - BoatTech - VHF Basics by Don Casey).
> 
> Regarding the use of one band over another, go to eCFR ? Code of Federal Regulations to see Title 47: Telecommunication, Part 80--Stations in the Maritime Services, specifically:
> 
> ...


Fascinating. I learned something. Thank you, and thanks for doing the homework in the CFR.

Given that there is a technical error on the same page of Gordon's text as the "VHF radio first" I take that with a grain of salt, but I also noted in the same section of the CFR as your citation:



> §80.367 General uses-radiotelephony.
> .
> .
> (d) Frequencies in the 2000-27500 kHz band will be authorized only to ship stations that in addition are authorized to use frequencies in the 156-162 MHz band.


Now we can quibble over what "authorized" connotes but this could easily be the basis for the statement that a VHF is required before installing other radios. If there are no other requirements elsewhere in Part 80 it only applies to MF/HF (SSB) relative to VHF. That would mean you can have a radar, Inmarsat, and EPIRB without a VHF but not an SSB. *grin*

The term "service range" is used three times in part 80, each time in a different context and not ever defined. I'd like to think that the extended practical range of Rescue 21 does not meet the intent of "service range." The common general range of 20-30 miles line of sight is probably the intent. Where range is reduced by topography I would hope "service range" would take that into account. I can think of a number of anchorages within just a few miles of one another that are out of VHF range of one another but that are easily within MF or low HF range.

As a practical matter this boils down to the following: two cruisers sitting a few miles apart in Narragansett Bay should not be chatting on 2079 kHz if they can hear one another on VHF. Add another cruiser at Block Island and the communication is permissible.

Also as a practical matter the nice folks at the FCC license bureau aren't enforcing the requirement with Form 605. That means compliance is up to the owner/operator.


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## fallard (Nov 30, 2009)

Tracking down the FCC rules on this topic isn't easy. We can imagine that the typical boater doesn't have the time or inclination to wade through arcane FCC documents and may inadvertently be non-compliant at times. 

Agree with your Narragansett Bay-Block Island example and the observation that Form 605 is not instructive on requiring VHF as a prerequisite for other RF communications gear.


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