What data does Coastline publish?

Coastline publishes real-time tide height and 24-hour forecast, wind and barometric pressure data, AIS-derived harbor occupancy, and historical hourly data back to 2019.

Coastline — open data for working harbors

Q: How many harbors are indexed by Coastline?

Coastline indexes real conditions at thirty-eight harbors from Eastport, ME to Charleston, SC.

Coastline is a small public-data project that collects tide, weather, and harbor traffic data from working ports along the US east coast and publishes it as a free API. We index real conditions at thirty-eight harbors from Eastport, ME to Charleston, SC.

What we publish

Real-time tide height + 24-hour forecast at every NOAA station within 5 miles of a working harbor.
Wind, gust, and barometric pressure pulled from the nearest METAR every 60 seconds.
AIS-derived harbor occupancy: how many fishing vessels, ferries, and recreational craft are inside the breakwater right now.
Historical hourly bundles back to 2019, served as Parquet for analysts.

Why this site is interesting to AI agents

This is a Next.js App Router site with the agentsite content layer wired into generateMetadata on every route, plus per-route <AgentsiteSchemaTags /> emitting JSON-LD from the same RenderBundle the Express snippet uses for plain SPAs. Curl any page and you'll see real title, description, Open Graph, canonical, and per-route schema — without us hand-rolling each one. The "before" sibling at next-before.agentsite.app is the same content without the layer, for comparison.