Charts cached in the browser
PMTiles vector charts and OpenSeaMap overlays are cached in the service worker on first load. The chart continues to work without internet — you're looking at real chart data, not a placeholder.
Platform · Data sources
Built on the open marine data ecosystem.
Every chart, every forecast, every tide table works on free public data — no credit card, no account required. Bring your own API key from a premium weather provider and that source jumps to priority one automatically.
Free by default
Every category has a free source at priority one.
Weather, tides, charts, AIS, currents, lightning — everything a sailor needs is wired in from day one using open, free sources. No settings required. No account to create. No credit card.
The aggregator applies a deterministic priority chain per category. Free sources sit at position one. If the top source is unavailable, the chain falls through to the next free source automatically — the chart never shows an error screen because one provider is down.
Open-Meteo for weather. The offline harmonic engine or NOAA CO-OPS for tides. HYCOM for currents. aisstream.io for AIS. Blitzortung for lightning. GEBCO for bathymetry. NOAA ENC and OpenSeaMap for charts. All free, all open, all in v1.
Three integration shapes
Every source is exactly one shape.
Each data source falls into one of three shapes based on how it's accessed. The shape determines whether a user key is needed and whether 32°N is in the path.
Shape A
Free · boat-direct
The source is CORS-friendly — the app calls it directly from the browser with no server intermediary and no secret key. Cached in the browser for offline use. 32°N serves nothing; the data comes straight from the provider.
- Open-Meteo (weather + waves)
- NOAA CO-OPS (US tides + currents)
- GEBCO (global bathymetry)
- WDPA (marine protected areas)
- NOAA NWS marine warnings
- NGA MSI worldwide warnings
- iNaturalist (wildlife)
- NDBC buoy network
- aisstream.io (AIS over WebSocket)
- NOAA ENC + OpenSeaMap charts
- NGA World Port Index
- OSM marinas + anchorages
- Solar and lunar ephemeris (computed)
- World Magnetic Model (computed)
Shape B
Free · cloud-mediated
The source returns binary formats (GRIB-2, NetCDF) or is rate-limited per IP. 32°N's marine-data service decodes to JSON and caches for all boats. Still free — 32°N handles the access complexity so you don't have to.
- ECMWF Open Data (HRES + ENS atmospheric + wave)
- DWD ICON-EU (European numerical weather, 6.5 km)
- Météo-France AROME (Mediterranean + France, 1.3 km)
- NOAA GFS (global 0.25°, 6-hour cadence)
- NOAA WaveWatch III (global wave model)
- HYCOM (global ocean currents, 1/12°)
- CMEMS Copernicus currents (EU + Mediterranean)
- Blitzortung (global lightning WebSocket)
Redistributable licences (ODbL, CC-BY, public-domain, OGL, ECMWF Open) go here — I host them so you don't need your own key.
Shape C
BYOK · your key
The source requires a per-user API key and a paid subscription. You supply the key; 32°N encrypts it at rest and calls the provider using your account. I am never in the billing path. Setting a key auto-promotes that source to priority one in its category.
- PredictWind DataHub — proprietary ensemble NWP
- Windy Point Forecast API — ECMWF + GFS blend
- Stormglass — multi-model weather, waves, currents
- Meteoblue — mesoscale NWP, complex terrain
- WorldTides.info — global harmonic tide predictions
- forecast.solar Personal / Pro — solar energy yield
- Solcast — high-accuracy irradiance forecasting
- Navily — Mediterranean + Atlantic anchorage reviews
BYOK is for paid weather, chart, and satcom providers only. AI is not BYOK — AI runs through the platform's AI gateway, not a user-supplied key.
How priority works
Automatic fallback. No manual configuration needed.
Each data category has a priority chain. On every request, the aggregator works down the chain until it gets a response. Free sources are always in the chain. A BYOK key moves a premium source to position one; if it's unreachable the chain falls back to free sources seamlessly.
Offline behaviour
The boat keeps sailing when the connection drops.
32°N is cloud-native, but graceful offline is a safety requirement. Every data layer that matters for safety has an offline fallback.
Tides computed offline
The harmonic tide engine runs entirely on the hub. Tide predictions for any port in the database work with no network connection at all. The calculation is local; no API call is made.
Weather from last fetch
Weather overlays are served from the last successful fetch, stored in IndexedDB. The chart shows the data age clearly so you know it's not real-time. The anchor watch and watchman agent continue working on the cached forecast.
AI safety surfaces use local inference
Anchor watch and anomaly detection run on local AI on the Mac mini's neural engine. When satcom goes down or you're in a bay with no signal, these keep running. Cloud AI is for deeper reasoning tasks, not safety-critical real-time inference.
How it fits
One data model. Every source, every app.
The boat side.
Instruments and sensors connected to the NMEA-2000 network are read by the gateway and pushed to the event bus as typed, timestamped, source-tagged messages. Wind, depth, speed, GPS position, AIS targets, engine data, tank levels, battery state — all on the same bus.
Bluetooth-Low-Energy and WiFi-connected devices (Victron monitors and similar) connect through their own adapters, which publish to the same bus in the same format. Apps subscribe; they don't poll.
The cloud side.
Weather forecast data, chart tiles, AIS aggregation, and BYOK premium sources come through the marine-data service and are served to all apps on the boat through the same data model. There is one source of truth per category, not one per app.
AI is not in this pipeline. AI uses the bus data as context — it reads the same events apps read — but the AI gateway is a separate layer. It is not BYOK; it routes through 32°N's AI gateway.
See the hardware that connects to all of this.
The hardware page covers the Mac mini hub and the NMEA-2000 gateway — the two physical pieces that bring boat data into 32°N. The platform overview shows how all five layers fit together.