Built an onboard AI after a bad afternoon on Lake Erie — happy to share the journey

Hello everyone,

New here, wanted to introduce myself properly.

I'm Don, based in Canada, Great Lakes boater on a 1994 Monterey 265 SEL. I came to marine electronics through the back door — not a background in the field, just a guy who got stranded on Lake Erie with a dead engine, 300 manuals on his phone, and a very strong motivation to never be in that situation again.

The short version: electrical short killed the engine mid-lake. Turned out to be a rusted cigarette lighter adapter someone had wired in decades earlier — crossed wires, no fuse. The fix was straightforward once I found the isolation switch. Finding it was the problem. The information existed somewhere in my documentation. Accessing the right piece of it quickly, in that moment, with that stress level — that was a completely different challenge.

That afternoon sent me down the OpenPlotter rabbit hole. NMEA2000, SignalK, a Raspberry Pi, and eventually a question I couldn't stop thinking about: what if the boat could read its own manual and watch its own sensors at the same time?

That question turned into about two years of building. What I ended up with is an onboard AI platform — d3kOS — that runs entirely offline on a Pi 4B, connects to the NMEA2000 network, ingests the actual vessel service manual, and provides real-time diagnostic assistance based on live sensor data. No cloud dependency. No subscription. Fully offline capable.

Current version is 0.9.1.2, in beta, free and open source under GPL v3 on GitHub.
I'm happy to go into the technical details on any of it — the NMEA integration, the offline LLM approach, the action boundary architecture, whatever is useful. This community looks like exactly the level of technical depth I've been looking for.

— Don (Skipper Don) github.com/SkipperDon/d3kOS

 

I love it.

About 100 thoughts come to mind.

One day I spent 4 hours trying to find a problem. Finally, I discovered a solid state DC voltage converter had a dead short,

Another time, I forgot to wire something disconnected for winterizing. That list is long.

But so many things AI could help with; especially on a per boat basis.

 

Can you explain a couple things?

1. what hardware is needed .. I don’t think the pi has n2k out

2. how are pages from a “manual” entered into the software engine?

 

How did a cigarette lighter socket "kill" the engine? Do you mean it blew a main battery fuse protecting the starter circuit?