MyPlotter
part of MaracaiboA minimal Android chartplotter that runs on the phone's own GPS and a sideloaded chart — no boat network needed.
I wanted a chartplotter in my pocket that still works when the boat’s systems are off. OpenCPN for Android was the obvious candidate, but it carries far more than I need; the right answer was a minimal Kotlin shell around a WebView, reusing the same S-52 renderer already proven on Maracaibo’s dashboard verbatim.
The chart is a purchased/licensed MBTiles file that arrives by the simplest safe path — hand it to the app, import it once, and it lives offline. Position comes from the phone’s own GPS first; if the boat’s SignalK server or an NMEA 0183 feed is on the same Wi-Fi, the app can merge that in, but the core plotter does not depend on either. North-up and course-up modes freeze below a speed threshold so the chart never spins on noise at anchor. A track manager, GPX import/export, MOB mark and course predictor fan are built in.
The APK is real and has been driven on an Android phone; the remaining acceptance is one outdoor trip to settle screen-off continuity, battery cost and course-up while actually moving.
- Next version drafted: track sync to cloud
- Renamed MyPlotter and installed on the Pixel
- Track manager gets its own screen
- Man overboard button and standalone build
- First run on a real phone: chart draws
- Android shell with tiles and GPS
- Phase 1: research and architecture, no code
- Read the artefact, not the manifest
I wrote up every permission the app asks for, reading them back out of the built package rather than off the source manifest. That is the…
- A chart that spins on noise is a lie shaped like an instrument
Decision. Course-up turns the chart under the boat — but below about a knot the rotation freezes at the last good heading and an amber…