Nema 2000 Backbone

Newsgroups Archive Prior to 2025
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The 38 year old Signet Marine instruments on La Reina are starting to provide warnings that they are nearing the end of life. I am starting the search for new instruments: wind, depth and speed. Of course the new instruments can be connected via the NEMA 2000 backbone system. Has anyone out there gone that route and if so where do you run the backbone? Did you run it under the cabin sole? Wire for the wind transducer down the mast with a connection at the base so the mast can be pulled. A short run back to a T for a drop cable to the speed depth transducer, then running back to line up with the electrical panel to connect power and then a run to the helm station to connect the displays and the GPS. The displays are in pods on either side of the compass rather than being mounted on the cabin bulkhead. At the moment I am considering having two displays. One can show speed, depth and temp. The other will display wind, true and apparent wind direction and speed. With the current Signet I one display shows speed through the water or depth but can’t show both at the same time. The other shows apparent wind angle and sped.

If you want to recommend a particular brand of instruments please feel free to do so along with an explanation aw to why you chose that brand over the others. I am considering B&G Triton 2, Raymarine or Garmin. The Signets were top of the line when they were installed but the new ones are very expensive so are not in the running.

Mark Powers
La Reina 26C
Vancouver, B.C.

2

Mark,

I think if you’re going to do a NMEA 2000 backbone (NMEA is short for National Marine Electronics Association), you’re not restricted to using all from the same manufacturer. The whole point of the standard is to make things “plug’n’play” across manufacturers.

I happen to have all >3 years old Raymarine on my boat, and for no good reason have had that on all my previous boats. So, I have no basis for comparison. I can tell you pros and cons of mine, but I don’t regard them as so stand-out that I’d say you gotta go that route.

One suggestion I’d make is to focus on comments from people who have relatively new equipment. There seems to have been a lot of restructuring and consolidation in the industry. How they used to be in the past may not be reflective of how they will be going forward.

My Raymarine instruments do the job. The installation manuals have been good enough that I’ve been able to put them in myself, and have had no problems resulting from the physical installation, and no product defects. The instruments hold up. The displays are pretty readable if you’re not wearing polarized sunglasses.

The problems I’ve had have stemmed from software. They update the firmware every so often and it pays to keep it up to date, because glitches do get fixed. However, you have to be careful to get the updates for all your instruments and install them in the right order. I missed one without realizing it, and spent weeks trying to figure out why my multi-function display would shut itself off and ten minutes later turn itself back on. The problem went away when I reinstalled the software.

One quirk that I found interesting was that my “Raymarine” wireless wind instruments (actually rebranded after Raymarine bought Tack-Tic) use their own GPS’s speed computation to compute true wind, but no other Raymarine instrument will accept that information. They all want to take the wind instrument’s apparent wind report and do their own computation from knotmeter report. So, even if you go with one “brand” you still can’t be sure everything really actually meshes.

Raymarine used to be a U.S. division of Raytheon. Raytheon spun it off, and I believe it went for a while on its own before becoming a subsidiary of FLIR, which specializes in high-tec night vision systems. They’re now based in the UK. Prices on instruments seem competitive, but the prices of accessories (e.g., cable connectors) strike me as, well, not quite Westerbekian, but still pretty high. On-line tech support has a good FAQs section, and has generally been responsive to email queries.

I went with Raymarine mainly because I started with a boat with no electronics, just holes where they used to be and cut cables leading from transducers. I quickly determined I needed an autopilot because I was single-handing, and got a decent price on the Raymarine autopilot (formerly Autohelm) and course computer. Once I had that, I started incrementally adding equipment, and stuck with Raymarine mainly from habit. I also was concerned about anyone fobbing off a warranty claim by blaming problems on a device’s interactions with a different manufacturer.

That said, with 20-20 hindsight, I’m not sure my brand loyalty was due to wisdom or cowardice.

Hope this is helpful. I don’t think any of your choices are bad ones.

– Bob
Solar Wind
Nonsuch 26C #143

3

One correction to my preceding remarks: I said my equipment was “>3” years old. I hit the wrong button. All my equipment is LESS than three years old.

– Bob
Solar Wind
Nonsuch 26C #143

4

I converted my former 1989 N30U to NEMA 2K after getting a Garmin 740 Chartplotter which I then coupled with a Garmin triducer for depth, water speed and temp. It was a pretty easy conversion which included a replacement pedestal guard (taller and larger diameter) to accommodate cables and wires coming from the backbone secured in the starboard side cabinet. Using the old depth transducer cable as a messenger I pulled the new 2K cable from the forward transducer location back to that compartment backbone. I ran another drop cable from the 2K backbone into the engine compartment and up through a hole drilled at one of the bases for the pedestal guard and out close to the Garmin 740. Power wires from the chart plotter also ran down that guard and over to the instruments circuit breaker for on/off power. As I was using a Raymarine wheel pilot I did not pursue connecting it tho the Garmin backbone although I understand that is possible with conversion cable (RayM to Garmin). I included a secondary Garmin display on the starboard cockpit bulkhead which had a drop cable to the backbone also. It gives me depth info when I’m not at the helm to observe depth readings on the 740.
It all worked so well that when I upgraded to 1989 N33 I did a similar NEMA backbone based around a Garmin 741 chart plotter. This time I included Garmin NEMA radar. Boat came with Raymarine wind instrument which works well but soon as it starts acting up I will be replace it with a Garmin NEMA 2000 wind instrument.
Here’s an old pic of my N30U helm view.

587000B8-49FC-477A-96BE-DB5FEF3ABFC2_1_105_c.jpeg640×480 73.2 KB

Old Standard Horizon wind display is seen above new Garmin depth repeater. Bracket on the pedestal guard below the chart plotter is to accommodate my old Garmin hand held 478 GPS should 740 ever fail. Boat is in my slip with 1.4 ft below the keel as seen on the chart plotter and the bulkhead display.

Ed Strazzini
S/v PELICAN N33 #36
Deltaville, VA

5

Bob,
Thank you for the information.
Where does the backbone cable run?

Mark Powers
La Reina 26C
Vancouver, B. C.

6

Bob and Ed somehow managed to avoid the headache that I encountered.

I installed a Garmin 742 since I liked the one on my N22, I also wanted a Raymarine EV100 autopilot.

Got everything installed and networked only to find that the EV100 wouldn’t hold a course. Raymarine help desk said it needed a software update.

That’s when I learned the Raymarine equipment can only be updated through a Raymarine multifunction display.

NO WHERE in sales literature or in installation manual does it mention that you must use their MFD to do upgrades. Had I seen that, I would have not done the install. They didn’t even put a USB port on the damn thing.

I had to get a Raymarine installer to bring an Axiom MFD to the boat and hook into the network. After going through the upgrade of the Axiom, he was able to upgrade the EV100 components via bluetooth and I now have a working autohelm. Of course, I can’t do any upgrades in the future.

I have written to Raymarine/FLIR for compensation for their receptive practice but have not yet received a reply (and I’m not holding my breath).

Raymarine apparently has now abandoned (see upgrade) the ng system for Raynet ethernet connection to the NEMA backbone.

So be careful and ask additional questions before mixing manufacturers because compatibility may not really exist.

You may need to cut and splice cables to get them run where needed. Readily available from Hodges and others…you will need magnifiers to see the damn little wires.

Joe
C26 #156
SEA HORSE

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Hi Mark

This is my first attempt to post...

I chose to run a Maretron micro NMEA2K backbone from stem to stern along the port side up high under the deck.

Didn’t want to run the network up the mast, so opted for mounting a Maretron WSO100 wind instrument on the bow pushpit and terminating the backbone inside it - works great under way and tells air temp and humidity too

At first I installed a small (5 inch) Maretron DSM150 display on the port bulkhead - it shows all the NMEA2K data that is on the backbone and allows one to configure the transducers easily - I liked the whole network thing so much I later installed a big MFD and went from there.

John Batchelor
Wind Rose
NS36 #27
Kirkland WA

8

Mark,

My backbone runs under the floorboards, into the engine compartment along the port bulkhead, into the port lazarette, where it connects to a power bus that runs through a conduit under the cockpit to one of the batteries in the starboard lazarette.

My suite of Raymarine electronics currently consists of an Axiom 7 MFD, RayMarine EV100 autopilot with P70s control head, EV-1 course computer, Autohelm 4000 motor, Seatalk network and fused power supply, T101 wireless wind instrument package (T112 + T120), and Micro-Talk Wireless Performance Sailing Gateway.

I’m awaiting delivery of a knotmeter transducer that I thought I didn’t need because GPS should be fine, but discovered is expected by the MFD and autopilot. (Note Joe Weinbrecht’s similar comments about things manufacturers forget to mention.)

I rely on a handheld radio, which is not integrated into the rest of the system.

Note that I do NOT have a connection to wind instruments on the mast. I have a wireless wind instrument on a spar at the bow which puts it about 12-14 ft above the waterline. That connects to a device mounted on deck near the halyard winch, which links it into the backbone through wiring running under the port coaming. I may move the wind transducer to the mast the next time the mast is pulled; the bridge to the wired system is placed so it will receive the wireless signal without interference either way.

I also chose not to deal with running cables (other than for the autopilot) through the wheel pedestal or guard. Again, the jury’s out as to whether that was wisdom or cowardice. Instead, I built a bracket on the port deck between the coaming and the stern pulpit, just aft of the gate. Cables from the MFD go through a sealing gland on the side of the coaming, and from there down to the Autopilot controller in the port lazarette. For using the MFD, I find it easy to just glance to my left from the helm.

I originally had the wireless wind display mounted there along with the MFD, but discovered that I wasn’t good at interpreting a display of wind angle off the bow when the display wasn’t oriented in line with the bow. So now that’s on a bracket on the wheel guard, which was easy because it’s wireless and solar-charged.

My boat came with two big round holes in the starboard side of the cabin, where original instrumentation had been. With topping lift, choker, and reefing lines coming over the cabintop there, I didn’t see the point in putting displays there that lines and passengers would prevent me from seeing, anyway. So, I covered those and put sheetbags there.

– Bob
Solar Wind
Nonsuch 26C, #143

9

You will also find that the cables are not very flexible especially at their connections and take quite a bit of space. I chose to mount the EV100, the ACU and the Backbone connector on a panel in the stbd qberth to the rear of the porthole so I wouldn’t have to do all that connectivity in a lazarette. The P70 control head is mounted rear of the engine control panel in the cockpit.
Unfortunately, when the built our boats, they never envisioned the electronics to come and put no conduits between the hull and interior skin.

Joe
C26
SEA HORSE

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You’re smarter than I was, Joe. The lazarette is a royal pain.

Locating the P70 control head starboard rear of the engine control panel also makes a lot of sense, since that space already has to be kept clear. Mine’s on starboard since I inherited holes in the boat there from previous autopilot installations that had been stripped out.

With 20-20 hindsight, my boat has panels above the quarterberths that give pretty good access to the areas under the coamings. Now that you make me think about it, I kinda wonder if I should’ve hooked up everything with some slack and then used that panel to stuff it under one of the coamings. The starboard side’s preferable for that, since there’s a lot more protrusions on port with the bolts for the winch and all.

– Bob
Solar Wind
Nonsuch 26C, #143

11

Thank you everyone.

Joe, thank you for the warning. I went to the local electronics store yesterday. The salesman started to talk about Raymarine. I asked about updating software given that I have a Lowrance Hds7 Gen 2 chart plotter. He confirmed updating software would be an issue. He then suggested B&G Trident instruments. I asked if I could update software using the Lowrance. He said he would have to get back to me.

When I was looking at chart plotters a few years ago the main three that were available in the size I was looking at were Garmin, Raymarine and Lowarance. Both the Garmin and the Raymarine used a magnet to hold the chart chip door closed. The magnets would through off the ship’s compass. Also at that time it took two small Garmin chips or one large chip (same cost as two small ones) to cover the sailing area. The Navionics chip that would work with the Lowrance would cover the sailing area for half the cost of the Garmin chip. Given those factors I went with the Lowrance. six months later Garmin changed its pricing and the large chip was the same price as the Navionics chip.

Anyway I would prefer not to buy a new chart plotter so I may be limited in my instrument choices.

La Reina is a classic so the electrical panel is just behind the head on the starboard side. There is a breaker switch on the panel for the instruments. The house batteries are located in the starboard quarter berth behind the holding tank. I will likely take the power for the backbone from the panel.

Mark Powers
La Reina 26C
Vancouver, B.C.

12

SEA HORSE has the same panel setup. The speed,depth and wind are mounted on the stbd side of the hatchway. I was going to take the 12v lead from the back of the instruments for other electronics. There was a 15amp breaker marked instruments…of course as soon as I powered up everything died…couldn’t find the blown fuse until I took the panel front off. Behind the 15 breaker was a 1.5amp fuse…since I had everything else fused, I put a 15 amp fuse behind the breaker and all is good now.

I’ve built a prototype of an electronics “center” next to the back of the three instruments at the hatch way and have centralized Hobbes meter (replaces dead one at tach), VHF radio,12vt outlet, charger display panel, and has room for the Xintex and AM-fm radio as well. Need time and cooler weather to reroute the AMFM speaker wires and the Xintex from under the 12v panel by the head. Once everything is relocated I intend to rebuild the prototype properly this winter with the boat 3 minutes away instead of 1.5 hrs as it was till I got her home.

Joe
C26 #156

13

I too have that panel set-up, and have also set up an additional electronics center to starboard of the hatchway in a tidy little cabinet that was apparently built to hide the back of where the original instruments used to be.

FWIW, my recollection is that my Raymarine installation manual called for a dedicated connection direct to the battery rather than being on a shared panel. I don’t have 100% confidence that my memory’s correct, nor do I recall why that would be needed. But, I would suggest checking that issue in the manuals for whatever you select before you get too far down the road.

On a previous boat with a Raymarine installation, the autopilot would crash every time I started the engines. I don’t have that problem on my Nonsuch. One possibility is that’s because I did a direct battery connection on this installation whereas on the other boat the manufacturer had put the system on the panel. Another possibility is that it’s entirely unrelated, and I’ve just been lucky so far.

In general, electronics on boats, both hardware and software, seem to be inventions of the devil. Most of the mechanical devices on my boat seem to be gifts from the angels. Sad admission for a retired computer scientist to be making, but that’s the truth.

– Bob
Solar Wind
Nonsuch 26C #143

14

I have been doing a bit more research. Turns out Garmin sells a device called a NEMA 2000 Network Updater that allows a person to update their Garmin instruments even if they don’t have a Garmin chart plotter. It is a small device that you connect to the backbone and accepts a SD chip. So far I have not been able to find out if Raymirine has a similar device or if the Garmin device would work with Raymarine instruments.

From what I can found out so far B&G does not have a similar device. Their manual states that if you don’t have a compatible MFD you need to contact a B& G dealer.

Mark Powers
La Reina 26C
Vancouver, B.C.

15

Some additional feedback on Raymarine…

I mentioned in a previous post that I’d been getting by without a knotmeter because GPS was sufficient, but was ordering one because the Raymarine wireless and wired couldn’t agree on true wind without one.

Well, it came, and the first thing I discovered was an annoying OOPS. The hype for the Raymarine multi-function instrument is that it provides one-stop shopping for all your information. As it turns out, that doesn’t mean that you don’t need the other instruments, it just means that they’re redundant. I learned that again inspecting the transducer I received. It turns out that the knotmeter transducer comes with wiring that doesn’t connect directly to the network.

The only way you can connect a Raymarine speed transducer to the Raymarine network is to buy an intermediary that it connects to, which you can then connect to the network.

Your choices of an intermediary are: either a speed instrument display ($160 and up), or an ITC-5 bridge ($275 or so).

You can, of course, buy an over-priced $25-35 Raymarine connector, instead, and do a cut-and-splice job yourself. But, that will void your warranties.

If only competition encouraged companies to invest their ingenuity into obtaining customer loyalty through quality instead of investing it in clever traps. What a wonderful world that would be.

Oh, well, back to the real world.

I look forward to hearing more about Garmin, and about experiences with mixed equipment.

– Bob
Soar Wind
Nonsuch 26C, #143

16

Bob,
Hodges marine was best source for splicer.
I used one to get NEMA cable to my Garmin 742 on helm guard and another to splice my transducer (which by the way had only 3 wires and could have been spliced and encased in heatshrink at no cost) .

I guess if we went with dealer installed equipment we would save aggravation while emptying our pockets instead.

Joe
C26
SEA HORSE

17

Thanks, Joe, I’ll look at Hodges.

Doing things myself is the source of my personal motto: “Sailing + Working on Boats = Two Hobbies for the Price of Three”.

If I had dealers do it, my motto would have to be: “Sailing = One Hobby for the Price of Four”.

– Bob
Solar Wind
Nonsuch 26C #143