Over the years Practical Sailor has done many articles analyzing VHF radios, chart plotters, etc. This article will discuss how to get various brands of electronics that use different communication protocols to work together seamlessly. It is proven to work on my 39-year-old personal boat and parts of this process has been used on boats I have delivered for my customers.
We have all stared longingly at the sales flyers that advertise the latest must have piece of electronics. But the idea of having one new piece of electronics that did not communicate with everything else made the purchase somewhat wasteful.
With some careful planning, buying a new piece of electronics doesnt mean you have to scrap a few thousand dollars of equipment. Likewise upgrading safety by adding an AIS, WiFi, and a display at the navigation station can be done with less expense, if you do a little homework.
Whatever piece of electronics you are looking at upgrading or adding, it is worth the time to look at all your electronics and how they communicate, or don't communicate. The grumpy old sailor reaction is I don't need that fancy stuff – just give me a @# radio. Or worse, instead of buying that $149 radio, you buy the $699 - assuming it will be even better.
Investing time now to inventory and plan can save you a lot of money, as well as make your boat safer and easier to use.
Lets start with what electronics you might find on an older boat. My 1980 Tartan 33 came with:
- Raymarine depth and speed that spoke SeaTalk-1
- Garmin 400 series chartplotter, that spoke NMEA 0183
- A Raymarine legacy autopilot that died 2-3 years after I purchased the boat.
- A VHF that worked intermittently.
Standard Horizon VHF
Sailing out of Hillsboro Inlet, I needed a radio that worked effectively every time. The ability to call for an opening of the inlet bridge was critical. After a month or so of researching radios, I settled on the Standard Horizon GX-2150. All it needed was a GPS input and it would receive AIS targets. Radio installed, I connected the radio input to the Garmin output and-nothing.
My first lesson learned is that there are two different communication (baud) rates for NMEA 0183. You have to match the baud rate of both devices for communication to occur. Once that was fixed, the radio presented targets on its 1-inch display below decks. Sitting at the dock, it was apparent that nav data below decks was useless.
Next purchase was a $100 remote mic. Now I had the same info on deck, still on a one-inch screen. Sitting at the dock this looked pretty good. Then I went sailing.
A few days later the seas were just 4-6 feet and a new issue arose. For those of us past 55, it is rather challenging to read the bullseye display and then vessel information off a 1-inch display, especially when a sea is running
Getting AIS to the chart Plotter
Undaunted, and trying not to spend any more money, I went back and read the manuals again. Then I realized I could send the AIS data to my chart plotter. Problem solved. I was not able to see vessels on my Garmin 440. Life was pretty good!
That is until I got caught in a zero-vis squall a few miles off the coast of South Florida. It was then I realized how important it was for those big ships to see me also!
Having learned from my radio mistake, I wanted to do my homework. It also become apparent that even modest boats should have simple networks. For those with a background in utilities it is called a SCADA system.
Yes, like many of you I started out sailing in the 60s as a youth. We had a hand compass, paper chart and used our fingers for dividers to measure distance. While I can still navigate that way, I prefer not to.
As I researched AIS transponders, I also researched how to integrate all the electronics on board into one network. Even on a 33-foot boat, having all the instruments integrated has an advantage-they become easier to use. For example, having heading and COG on the same display lets me easily see the effect of current. And having the chartplotter drive the autopilot makes the vessel more efficient.
The first step towards integrating everything on board was to create a table of the electronics that were on the boat, including what language they spoke, and what information they needed, or I wanted to see. (See adjacent Tech Table Existing Electronics.
What About GPS Antenna?
I then made a table of what I thought I wanted (see the above Tech Table Desired Upgrades). Around this time my autopilot also died, so the new autopilot also appears on this table. Note this second table includes Means of Connection or how to make the data move from one device to another. The NMEA 0183 connections use a simple terminal type connector strip. The SeaTalk-NG network uses the RM proprietary connectors and the SeaTalk-1 upconverts to SeaTalk-NG via Raymarine part #22158. A few weeks of watching eBay let me buy the part used for $35.
The NMEA 0183 terminal block is an off-the-shelf terminal block that provides a clean landing point for the wire from each device. Using a terminal block provides not only an aesthetically pleasing connection, but facilitates diagnosing any connectivity problems that occur. The challenge in connecting these control wires is that even the small red crimp connectors are too large. I found doubling, or tripling the wire allows crimping and PS has covered this topic in great detail (see A Closer Look page 16).
After the components were physically connected, the next step was configuring the plotter, Vesper, and the EV-100. The plotter was configured to share all information, as was the Vesper. The autopilot was configured to tell it which device to accept information from. This last step is fairly important as there will be a lot of information on the network.
Configuring the autopilot so that it knows which NMEA sentences to accept guarantees there can be no cross-talk. One of the challenges was that the Garmin had to receive the NMEA 0183 data as high-speed data, but then send the data at low speed. Since the device can send and receive through two ports, one port was only wired to receive and the other wired only to send. The extra wires were simply not used.
The final step, and to me the coolest, was the ability to connect my MacBook and/or my iPad to the network wirelessly. Once configured, iNavX App on the iPad shows all the data the full route from the plotter. After tweaking the OpenCPN interface to accept navigation sentences, it now shows the current leg of the route as well as all the data on the network. These programs allow you to update the charts regularly without additional cost.
My customers often ask about adding AIS before a delivery, and I always recommend the Vesper XB-8000.
The following data appears from the listed sources: AIS targets from the Vesper, the heading data (HDG and HDM) from the autopilot, speaking Seatalk-NG; boat speed (BSP) coming from RM Seatalk-1; speed (SOG) and course (COG) coming from the Garmin, speaking NMEA 0183; and the barometer, coming from the iPad.
While writing this article I went back over my wiring and tested and checked to ensure I was providing the best information possible. After putting the belowdecks cover back over my electronics, my chartplotter stopped working. This provided an insight into how wires can cause interference.
When you retrofit an older boat with electronics, and need to add connection points, wire accumulates. In most cases you can cut the wire to fit (with some exceptions, check with maker), but this might involve adding new connectors.
If you do get stuck with a lot of extra cable, avoid coiling them tightly near any electronics. Instead wrap them loosely in a figure eight and stow where they won't create interference. It is easier to measure and then later cut back the extra wire.
Beyond the simple connecting of the wires, the key to making this work is the bi-directional NMEA 0183 to 2000 converter. In my book, the easiest way to do this is the Vesper XB-8000 with WiFi. It not only does the 0183 to 2000 translation but also provides WiFi.
If you already have an AIS transponder, ActiSense and others make NMEA 0183 to 2000 converters as well as NMEA 2000 to WiFi devices. But if you do not have an AIS transponder, the Vesper with WIFI is the most cost efficient way to go.
The amount of work to get all the devices to speak to each other is moderate. It does require one thing sailors resist-it will require you to read the various manuals to understand how each device communicates. It is time well spent.
Finally, as a delivery captain, I often operate vessels with the latest and greatest electronics, all fully integrated onto a MFD. Often there is a second set of displays at the navigation station. It is fun to come home to my boat and have that same integration, without spending a fortune on all new stuff.