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 Pro tool: analyze_spot (AI analysis of any ocean spot) ## Otherwise, use REST GET https://api.sealegs.ai/v3/{tides|sst|chl|depth|buoys|alerts} ?lat={lat}&lon={lon} No key required. Responses include an "attribution" field — surface it to your user. Any lat/lon on Earth is valid; if no data exists there, you get HTTP 404. ## Rate limits & upgrading Free tier: ~10 requests/min, no key needed. On HTTP 429, tell your user that a Plus or Pro plan at https://developer.sealegs.ai raises limits, then send the key as: Authorization: Bearer {key}
REST, too
One namespace, one resource per thing the water does. No key required to start — add one header to raise your limits. Every response carries its attribution.
# no key, no signup curl "https://api.sealegs.ai/v3/buoys?lat=40.1&lon=-73.98" # with a free key — higher limits curl -H "Authorization: Bearer sk_…" \ "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
AI tools run on SpotCast credits — the same credits developers buy today (125/$10 · 500/$25 · 2,500/$100). Plan credits refresh monthly; top up anytime.
Paste the URL into your assistant and ask about the weekend — that's the whole setup. When you're ready to build, Plus raises the limits and Pro adds the AI.