Ah, that's my fault for not making the error handling clearer in the UI. If the map is blank, it usually means the backend is missing the .env file with the free API keys (AISSTREAM_API_KEY and N2YO_API_KEY), so it's silently failing to fetch the streams.

Did the terminal throw any Python FastAPI errors, or did it just serve the Next.js frontend? I'm going to push an update later today to show a prominent "Backend Disconnected / Missing API Keys" warning on the UI so it doesn't just look dead. Thanks for testing it!