What we did, what it cost us in time, what went wrong, and enough detail that you could do it yourself. Including the bits where we got it wrong first.
What we built, how, and what went wrong
Every one of these is something actually running on this boat, written up with enough detail that you could build it yourself — including the wrong turns, which are usually the useful part.
Click any of them.
Marine radar and sonar imagery are proprietary — not encrypted, just undocumented. We captured both off our own instruments and worked out what the bytes meant. Both now draw on a Raspberry Pi, on a screen no manufacturer sold us.
Every port, how to power it from a boat, which cables it takes, how to get it online with no screen, and how its Bluetooth actually behaves — including where Pis fail afloat.
No smart alternator regulator. A lead-acid buffer bank, relays off the ignition, and six Victron DC-DC chargers you can step up and down while the engine runs. Includes how to wire a relay.
Bluetooth or cable, which we used and why, and what cell balancing and the temperature cutoffs actually mean — including the one setting that will quietly destroy a bank.
The Ekrano GX, Venus OS Large with Signal K and Node-RED built in, the one-battery-bank limit nobody mentions, and the custom power grid page we built instead.
A custom script that pulls ships from far beyond our own receiver's range onto the chart, and why we feed our own AIS to the internet in return. Source code on request.
Position, place name, distance run and the day's average wind and boat speed, written down every day automatically — plus the maintenance schedule that goes with it.
A nine-axis sensor giving heel, pitch and — the hard one — heave. How up-and-down motion becomes a real significant wave height.
Marine VHF, weather radio, aircraft, AIS and 433 MHz sensors from one cheap USB stick — plus the weather-satellite part that we have never managed to make work, and why.
Reach every screen aboard from a phone on the other side of the world, and the security rules that stop it becoming somebody else's keyboard.
LiFePO4 house and nav banks, why we went lithium at all, charge acceptance and C-rate, cell balancing, and the storage voltages that decide how long your cells last.
A Pi, a CAN hat, a stacking header, a barometer and temperature probes watching the Fischer Panda. How it's built, what it does, and how to build your own.
How routing actually works, GRIBs and polars explained, where to get them free, and turning your boat into a weather station other sailors can see.
Ollama and Qwen running locally with no internet, Claude Code as the teacher, and every manual aboard loaded in so it can troubleshoot and find part numbers.
BotFather, API tokens, connecting it to the boat, and the real limits — including the one that catches everybody out.
One box as router, N2K gateway and weather terminal. How the whole boat sits behind it, and what it becomes once Starlink is the only link you have.
NMEA 0183 and NMEA 2000 taken apart character by character and bit by bit, with real captures off this boat. Start here if the rest of it doesn't make sense yet.