Photo by Andy Schell
Nerd alert: We’re talking networks and data this month, none of which is really integral to the safe running of a boat as far as seamanship is concerned, but all of which is addictingly fun and surprisingly enlightening. Specifically, I’m looking at NMEA 2000 networks and how to get the most flexible use from them without being tethered to a built-in multifunction/chartplotter display. Turns out, this is harder than I thought.
I’d never had a boat with a modern NMEA 2000 (N2K) network built from scratch, so with the refit of Falken (our new-to-us Farr 65) nearly complete, this has been an interesting process to learn about and to implement, and a strangely opaque topic to find good, unbiased information on.
Unlike most modern, networked electronics packages, Falken’s design does not rely on a central chartplotter screen, aka MFD (multifunction display). I hate MFDs. They are obscenely expensive, don’t work nearly as smoothly or intuitively as a laptop or iPad, aren’t portable—I could go on. Instead, Falken’s only installed large screen is a dedicated commercial Furuno Radar, the 1835 model, which we’ve had on our other boat, Isbjörn, since 2018. It serves one purpose extremely well and quite simply just works.
Most people nowadays will have navigated on a tablet or smartphone, and if you have 4G coverage, you’ll likely have GPS and even internet-based AIS data displaying on your device’s charts automatically. Once offshore and off the grid though, you need a way to get that data from an onboard source into the mobile device.
Historically we have done that via a N2K Wi-Fi gateway, specifically one built into the Vesper line of AIS transceivers. On Isbjörn and Icebear, we’d used their long-established XB-8000 AIS transponder, which doubles as a Wi-Fi gateway and can transmit most data it’s receiving out over the Wi-Fi network. Falken has Vesper’s newer Cortex hub, which effectively does the same thing with a few extra bells and whistles (integrated VHF and remote monitoring).
I’d never previously needed to transmit anything beyond your standard navigational data—wind, depth, speed, heading, SOG, AIS, etc.—over a Wi-Fi network, because that’s all the data we had sensors for. But on Falken, we have more sensors collecting more data, including N2K tank sensors, an N2K module on the Beta 85T engine, and N2K battery information. Well, as I discovered recently to my chagrin, when you dig deep into the manuals of many N2K Wi-Fi gateways (including those from Vesper), you’ll find you cannot in fact transmit all of the data that you want to, only the selected data they’re programmed to transfer.
The reason for this is nerdy. What a typical Wi-Fi gateway is actually doing is taking the more modern N2K data protocol from the network, translating it to the older, simpler NMEA 0183 protocol, then transmitting that over the Wi-Fi network. Problem is, some newer N2K data protocols don’t translate to 0183, thus a standard gateway cannot transmit it. Such is the case with tank and engine sensors, as well as many autopilot 9-axis motion sensors, to name a few.
I was stumped. Here I had designed this entire system specifically to not require the use of an expensive central MFD, and yet much of the data I have available is only visible to a built-in MFD screen that can read it!
Thankfully, I’m not the only one who has discovered this frustrating problem. The limitation isn’t technology, but bureaucracy. Mobile app developers don’t bother with programming N2K protocols into their apps because it’s costly for them to subscribe to the N2K coding libraries. And, the number of users who don’t have a built-in MFD and who use their mobile devices for more than simple electronic chart navigation is minuscule.
But, like me, they do indeed exist. Nerds to the rescue. As both N2K and mobile device use on boats grow in ubiquity, app and hardware developers are inventing new ways to get all N2K data off the hard-wired network and broadcast-able over Wi-Fi, MFD manufacturers be damned (and anyway, how many freakin’ screens do we need in our lives now!?).
The solution relies on hardware and software. Modern N2K Wi-Fi gateways, like the Digital Yacht NavLink2 we have, offer a “raw N2K” transmit mode, which in addition to translating the data to 0183 for standard mobile apps, provides a raw data stream in the N2K format from all onboard sensors. Pair that with a forward-thinking software app like the brilliant, simple, and elegant NMEA Remote, whose developer has incorporated raw N2K into the software, and you finally have the solution I’ve been looking for—all of your N2K data, streamed wirelessly to any device, all of the time. (Incidentally, there is a nascent open-source solution evolving as well, called Signal K. Google it).
In practice, instead of an expensive, permanently installed, and almost instantly obsolete MFD, we use the iPad and iPhone approach. Falken gets a dedicated, large-screen iPad Velcroed to the nav desk bulkhead and plugged into 12V power. That iPad runs our navigation software, which changes depending on where on earth we are, and additionally runs NMEA Remote, which can show all the rest of the N2K data we need, like tank levels, engine info, etc. NMEA Remote can log that data to boot, so an old iPhone wiped clean and running only NMEA Remote can double as your voyage recorder for any data on the network you want to log. A second, smaller iPad is portable, for use in the cockpit.
Additionally, every skipper and mate who comes aboard has a smartphone, and they can access all navigation and boat data on the same network while resting in their bunk on their phones—instant access from anywhere onboard.
Of course, there is a fragility risk in wirelessly transmitting data, so we do have a minimum of hard-wired, 4-inch Furuno instrument MFDs that can show all the data too—one at each helm, two at the nav station—plus a N2K-to-USB gateway that will send the same data to a laptop via hard-wired USB. Redundancy is, of course, the key for an oceangoing boat.
And it goes without saying (I hope) that all of this is really just for the cool factor. Falken of course carries paper charts, a handheld GPS, a sextant, and crew who are trained in how to use all that stuff without missing a beat should our network fail. But damn, it is pretty cool!
April 2023
