Every boat project has a turning point. For me, it came on Black Friday.
I’d been limping along with a 1990s Lowrance fish finder — the kind of unit that belongs in a museum more than on Lake Erie. It showed a boat icon floating on blue nothingness. No detail, no charts, no real situational awareness. It was time to move on.
Out With the Old, In With the Garmin
The deal was too good to pass up: a new Garmin fish finder/chart-plotter. Suddenly, I had modern mapping, depth, and the ability to expand into a full electronics suite. But the Garmin wasn’t just a replacement — it was the start of a bigger plan.
Building the Backbone: NMEA 2000
If you want your electronics to talk to each other, you need a common language. That’s where NMEA 2000 comes in. Think of it as the backbone of a digital boat: one cable “spine” that lets devices share data — GPS, depth, engine info, fuel, weather, and more.
By adding an NMEA 2000 backbone, I wasn’t just installing a fish finder. I was laying the foundation for everything else I want to do.
OpenPlotter + Raspberry Pi
Of course, I can’t resist open source. Alongside the Garmin, I set up OpenPlotter running on a Raspberry Pi 4B. With the Copperhill PICAN-M hat, the Pi connects directly to the NMEA 2000 network.
That means I can:
- Capture and log all the boat’s data
- Build custom dashboards
- Stream information to tablets or phones over Wi‑Fi
- Experiment with automation and alerts
It’s the bridge between the commercial marine world and the DIY hacker world.
Making Analogue Digital: CX5106 Converter
Here’s where it gets really interesting. Boats like mine are full of analogue gauges — tachometers, fuel, oil pressure, trim. They look great, but they don’t talk to anything.
Enter the CX5106 Multi-function NMEA 2000 Signal Converter. This little box takes the signals from those analogue gauges and converts them into digital data. Suddenly, my old dials can also show up on the Garmin screen or inside OpenPlotter.
That means:
- Engine RPM, fuel, and trim data on one digital display
- Redundancy — analogue gauges stay, but now I have digital backups
- A step closer to automation and smarter alerts
Why This Matters
This wasn’t just a Black Friday deal. It was the first real step in turning my 1994 Monterey into the boat I’ve been envisioning:
- Analogue bones, digital brains
- Open source at the core
- A foundation that can grow into voice control, automation, and smarter navigation
The Garmin gave me charts. The NMEA 2000 backbone gave me integration. The Raspberry Pi gave me flexibility. And the CX5106 gave me a way to bring the old gauges into the future.
The project boat is becoming a platform.