Currents API

Authentication

The currents API is open and does not require authentication.

Rate Limits

The currents API shares the tides API's limits:

• 100 requests per minute per IP address
• 10,000 requests per day per IP address

If you need higher limits for a production application, please contact us.

A First Request

Slack water and the strongest flood and ebb at the current station nearest a point, for the next seven days:

curl "https://api.openwaters.io/currents/events?latitude=48.406&longitude=-122.643"

Error Handling

Errors are returned with appropriate HTTP status codes and a JSON body with a message, the same shape as the tides API.

Signed Speeds

Speeds are in knots along the station's flood axis. Positive is flood and negative is ebb. Responses carry the station's floodDirection and ebbDirection in degrees true when it publishes them.

Events

Each event has a kind: slack, maxFlood, or maxEbb. Maximum flood and ebb also carry a direction in degrees true when the station has one. Slack carries the small residual speed left at the turn. The timeline endpoints return a signed speed every 10 minutes instead.

Depth Bins

Some stations predict currents at several depths, called bins. A station ID on its own selects the primary bin, the one NOAA predicts by default. Append @N to select bin N, as in /currents/stations/noaa/EPT0003@11. Every station lists its bins in bins, primary first, and station searches return each station once, at its primary bin.

Canadian Stations

Canadian Hydrographic Service stations are listed so you can show them, but CHS terms do not allow its predictions to be redistributed. Their prediction endpoints return 451 with a link to the official CHS predictions, and station listings mark them predictions: false. The nearest-station endpoints return that 451 rather than answering for a station farther away. Stations with no prediction model return 404.