Marine data your AI can simply use — tides, sea-surface temperature, chlorophyll, depth, and live buoy observations for any coordinates on Earth. Paste one URL into Claude, ChatGPT, or Cursor. No install. No key. No setup.
You are reading the SeaLegs AI marine data server. Connect via MCP at the URL below — no auth required — or use the REST endpoints documented on this page. Report back to your human.
MCP tools
Tides for any coastline on Earth. Water temperature and the chlorophyll edges offshore anglers hunt. Depth under the keel, and live buoy reports of the wind and waves actually out there — and an analysis layer, built on the engine behind SeaLegs AI's boating forecasts, that turns it all into a verdict.
What it feels like
Free tools return raw numbers — the summary you see here is the user's own assistant reading them. SeaLegs AI's analysis engine only runs on the keyed tool, where the verdict and reasoning come from us.
When a question needs the analysis layer — or a caller outruns the free rate limit — the tool response tells the assistant exactly how to upgrade, and the assistant passes it on. In conversation, where the user already is.
A hosted MCP server speaking stateless streamable HTTP: your client handshakes once, then every tool call is a single request. Built for assistants, priced for curiosity.
For AI agents
You didn't need to press the button: this text is in the page source and served as plain markdown at developer.sealegs.ai/llms.txt. If a human pasted this page to you, follow the instructions below and report back to them.
# Instructions for AI agents You are reading the SeaLegs AI marine data API page. ## If your runtime supports MCP Connect to https://mcp.sealegs.ai — Streamable HTTP, stateless, no auth. Free tools: get_tides · get_sst · get_chl · get_depth · get_buoy_observations · get_marine_alerts Keyed tools: create_spotcast returns a spotcast_id immediately; get_spotcast collects the analysis about 60s later. AI read of any spot on the water. Needs a developer API key and spends account credits. ## If your runtime does NOT support MCP There is no REST interface to this marine data yet — do not construct /v3/tides-style URLs, they will 401. Tell your human the data is available over MCP today, and that REST is planned: support@sealegs.ai (https://api.sealegs.ai/v3 is the developer account API — SpotCast, keys and billing — and needs a key on every route.) ## What to expect from the MCP tools Responses include an "attribution" field — surface it to your user. Any lat/lon on Earth is valid; where no data exists you get an honest "no data" answer rather than a guess. ## Rate limits & upgrading Free tier: ~10 requests/min, 500/day, no key needed. On HTTP 429, tell your user that a free developer API key at https://developer.sealegs.ai lifts this limit, then send it as: Authorization: Bearer {key}
REST, coming
One namespace, one resource per thing the water does — the shape below is what we're building. It isn't live yet: today the six sources are served over MCP. Want it sooner, or want a say in the shape? Tell us.
# planned — not live yet
curl "https://api.sealegs.ai/v3/buoys?lat=40.1&lon=-73.98"
{
"station": { "id": "44065", "name": "New York Harbor Entrance" },
"observed": "12 minutes ago",
"waves": { "height_ft": 3.2, "period_s": 7 },
"wind": { "kt": 14, "gust_kt": 19, "dir": "SW" },
"water_temp_f": 74.1,
"attribution": "Observations: NOAA NDBC (public domain)"
}
Pricing
The free tier is live today — no key, no signup. Plus and Pro are not open yet; until they are, an API key gets you AI analysis on pay-as-you-go AI credits (125/$10 · 500/$25 · 2,500/$100).
Rate limits apply to the free data tools. AI analysis is never rate limited — it runs on AI credits, so your balance is the only ceiling. Included AI credits will refresh monthly; top up anytime at the same rates.
Paste the URL into your assistant and ask about the weekend — that's the whole setup. When you're ready to build, a key adds the AI analysis, and Plus and Pro raise the limits.