Marine Weather, Wave, Swell & Sea Forecast Scraper

Here is one real result, with every field the actor returns:

{
  "input": "Nazare, Portugal",
  "resolvedName": "Nazaré",
  "country": "Portugal",
  "admin1": "Leiria District",
  "latitude": 39.7083,
  "longitude": -9.125,
  "timezone": "Europe/Lisbon",
  "observedTime": "2026-08-21T12:15",
  "waveHeight": 2.14,
  "waveHeightFt": 7.02,
  "wavePeriod": 7.95,
  "waveDirection": 333,
  "waveDirectionCompass": "NNW",
  "windWaveHeight": 1.12,
  "windWaveDirection": 350,
  "windWavePeriod": 4.1,
  "swellWaveHeight": 1.8,
  "swellWavePeriod": 7.75,
  "swellWaveDirection": 327,
  "swellWaveDirectionCompass": "NNW",
  "seaSurfaceTemperatureC": 17.8,
  "seaSurfaceTemperatureF": 64,
  "oceanCurrentVelocity": 0.6,
  "oceanCurrentDirection": 252,
  "seaStateDouglas": 4,
  "seaStateLabel": "Moderate",
  "forecastDays": 3,
  "forecast": [
    { "date": "2026-08-21", "waveHeightMax": 2.22, "swellWaveHeightMax": 1.84, "wavePeriodMax": 8.05, "waveDirectionDominant": 331 },
    { "date": "2026-08-22", "waveHeightMax": 1.86, "swellWaveHeightMax": 1.82, "wavePeriodMax": 9.5, "waveDirectionDominant": 329 },
    { "date": "2026-08-23", "waveHeightMax": 2, "swellWaveHeightMax": 1.88, "wavePeriodMax": 10.65, "waveDirectionDominant": 282 }
  ],
  "historyDays": 92,
  "historyStart": "2026-05-21",
  "historyEnd": "2026-08-20",
  "avgWaveHeight": 1.45,
  "maxWaveHeight": 3.16,
  "maxSwellHeight": 3.1,
  "roughestDay": "2026-06-05",
  "roughestDayWaveHeight": 3.16,
  "pctDaysRough": 10.9,
  "aiSmallCraftAdvisory": true,
  "aiSurfConditions": "The waves are moderate, with a significant height of 2.14 m, suitable for experienced surfers.",
  "aiBoatingSuitability": "Conditions are challenging for small boats and kayaks due to moderate wave heights.",
  "aiFishingConditions": "Fishing may be difficult due to the moderate sea state and wave conditions.",
  "aiSwimSafety": "Swimming is not recommended due to the moderate wave heights and currents.",
  "aiSummary": "Moderate conditions warrant caution for small craft and swimmers.",
  "source": "Open-Meteo Marine",
  "observedAt": "2026-08-21T11:24:03.726Z",
  "error": null
}

The most complete marine conditions scraper available. It returns the full wave field decomposed into total wave, wind-wave and swell with direction and period for each, plus sea surface temperature, ocean surface currents, a derived Douglas sea-state label, and a multi-day wave forecast, for any coastal spot by name or coordinates. Most marine scrapers give you wave height alone.

📥 Input · 📤 Output · 💰 Pricing · ▶️ Examples

Table of contents

• What it does
• Use cases
• Quickstart
• Input reference
• Output reference
• Example output record
• Run via API and CLI
• Fetch results
• Billing and limits
• FAQ and troubleshooting

What it does

The actor takes a list of coastal locations, resolves each one to ocean coordinates (a place name is geocoded for you, or you pass a latitude,longitude pair directly), and returns one normalized marine record per location. Each record carries the current sea state and a daily wave forecast for the requested window.

For every location you get the total significant wave height (in metres and feet), the wave period and direction (degrees plus a 16-point compass label), and the same three values broken out separately for the locally wind-driven wind-wave and the distant-generated swell. On top of that it returns sea surface temperature (Celsius and Fahrenheit), ocean surface current velocity and direction, and a derived Douglas sea-state code (0 to 9) with its plain-language label (Calm, Smooth, Slight, Moderate, Rough, Very rough, High, Very high, Phenomenal). A compact forecast array gives the daily max wave height, max swell height, max wave period and dominant wave direction for each forecast day.

Marine conditions are defined only over ocean grid points. If a location resolves to an inland or off-grid point, the actor returns an honest error record for it (and is not charged) rather than fabricating values or crashing.

Use cases

• Surf forecasting. Track swell height, swell period and swell direction separately from local wind-wave chop to judge wave quality at a break.
• Shipping and marine logistics routing. Monitor wave height, sea state and ocean currents along a route or at ports to plan safer, faster passages.
• Offshore wind and energy operations. Check significant wave height and sea state windows for crew transfers, installation and maintenance vessels.
• Fishing. Combine sea surface temperature, current and sea state to decide where and when to fish, inshore or offshore.
• Coastal tourism and beach safety. Feed wave height, sea state labels and swim-safety context into beach and resort dashboards.
• Ocean research and monitoring. Pull consistent wave, swell, SST and current series for many coastal points into JSON, CSV or Excel.
• Insurance and risk. Use the 92-day history add-on to quantify how rough a stretch of coast has been (average and max wave height, share of rough days).

Quickstart

Open the actor, paste this into the input, and press Run. It returns current marine conditions plus a 3-day wave forecast for two well-known coastal spots.

{
  "locations": ["Nazare, Portugal", "Pipeline, Hawaii"],
  "forecastDays": 3
}

Each item in locations can be a coastal place name (geocoded automatically) or a latitude,longitude pair such as "33.6,-118.3". One record is returned per location.

Input reference

Field	Type	Required	Default	Description
locations	string[]	no	(none)	Coastal locations to fetch. Each item is a place name (for example Nazare, Portugal, Pipeline, Hawaii), auto-geocoded, OR a latitude,longitude pair such as 33.6,-118.3. One record per location. Use coastal or offshore points; marine data is only defined over the ocean grid.
forecastDays	integer	no	3	Days of daily wave forecast to include per record (0 to 7). 0 returns only the current snapshot.
includeHistory	boolean	no	false	Opt-in add-on. Adds a 92-day marine history summary per location (average and max wave height, max swell, roughest day, percentage of rough days). Billed only when a real history series is returned. Paid Apify plans only.
aiMarineAdvisory	boolean	no	false	Opt-in add-on. Adds an AI-written marine advisory per location (small craft advisory flag, surf, boating, fishing, swim safety, summary). Billed only when a usable advisory is produced. Paid Apify plans only.
maxResults	integer	no	10	Maximum locations to return in one run. Free Apify plans are capped at 10.

Output reference

One dataset item per location. Types are string, number, integer, boolean, array, or null when the source value is absent.

Field	Type	Description
input	string	The location string you passed in.
resolvedName	string	Resolved place name (from geocoding), or the lat,lon you passed.
country	string	Country of the resolved location, or null for a raw coordinate.
admin1	string	State or region of the resolved location.
latitude	number	Latitude of the marine grid point used.
longitude	number	Longitude of the marine grid point used.
timezone	string	IANA timezone of the location.
observedTime	string	Local time of the current observation.
waveHeight	number	Significant wave height in metres.
waveHeightFt	number	Significant wave height in feet.
wavePeriod	number	Wave period in seconds.
waveDirection	number	Mean wave direction in degrees (0 to 360).
waveDirectionCompass	string	Wave direction as a 16-point compass label (N, NNE, NE, ...).
windWaveHeight	number	Wind-wave (locally wind-driven) height in metres.
windWaveDirection	number	Wind-wave direction in degrees.
windWavePeriod	number	Wind-wave period in seconds.
swellWaveHeight	number	Swell (distant-generated) wave height in metres.
swellWavePeriod	number	Swell wave period in seconds.
swellWaveDirection	number	Swell wave direction in degrees.
swellWaveDirectionCompass	string	Swell direction as a 16-point compass label.
seaSurfaceTemperatureC	number	Sea surface temperature in degrees Celsius.
seaSurfaceTemperatureF	number	Sea surface temperature in degrees Fahrenheit.
oceanCurrentVelocity	number	Ocean surface current velocity in km/h.
oceanCurrentDirection	number	Ocean surface current direction in degrees.
seaStateDouglas	integer	Douglas sea-state code 0 to 9 derived from wave height.
seaStateLabel	string	Douglas sea-state label (Calm, Smooth, Slight, Moderate, Rough, Very rough, High, Very high, Phenomenal).
forecastDays	integer	Number of forecast days requested.
forecast	array	Daily forecast points: date, waveHeightMax, swellWaveHeightMax, wavePeriodMax, waveDirectionDominant.
historyDays	integer	Days covered by the 92-day history (history add-on).
historyStart	string	First day in the history window (history add-on).
historyEnd	string	Last day in the history window (history add-on).
avgWaveHeight	number	Average daily max wave height over the history window (history add-on).
maxWaveHeight	number	Max wave height over the history window (history add-on).
maxSwellHeight	number	Max swell height over the history window (history add-on).
roughestDay	string	Roughest day in the history window (history add-on).
roughestDayWaveHeight	number	Max wave height on the roughest day (history add-on).
pctDaysRough	number	Percentage of history days with max wave height above 2.5 m (history add-on).
aiSmallCraftAdvisory	boolean	Whether an AI small-craft advisory is warranted (AI advisory add-on).
aiSurfConditions	string	AI surf conditions assessment (AI advisory add-on).
aiBoatingSuitability	string	AI boating suitability assessment (AI advisory add-on).
aiFishingConditions	string	AI fishing conditions assessment (AI advisory add-on).
aiSwimSafety	string	AI swim safety assessment (AI advisory add-on).
aiSummary	string	AI plain-language summary of conditions (AI advisory add-on).
source	string	Data source.
observedAt	string	ISO 8601 timestamp of when the record was collected.
error	string	null on success. On a location that cannot be resolved or has no marine data, a single record with a populated error field is written instead and is not charged.

Example output record

Real record from a live run (input {"locations": ["33.6,-118.3"], "forecastDays": 3}), a coordinate off the Southern California coast:

{
  "input": "33.6,-118.3",
  "resolvedName": "33.6,-118.3",
  "country": null,
  "admin1": null,
  "latitude": 33.625,
  "longitude": -118.2917,
  "timezone": "America/Los_Angeles",
  "observedTime": "2026-08-21T04:15",
  "waveHeight": 0.72,
  "waveHeightFt": 2.36,
  "wavePeriod": 8.7,
  "waveDirection": 247,
  "waveDirectionCompass": "WSW",
  "windWaveHeight": 0,
  "windWaveDirection": 278,
  "windWavePeriod": 0,
  "swellWaveHeight": 0.72,
  "swellWavePeriod": 8.7,
  "swellWaveDirection": 247,
  "swellWaveDirectionCompass": "WSW",
  "seaSurfaceTemperatureC": 20.6,
  "seaSurfaceTemperatureF": 69.1,
  "oceanCurrentVelocity": 0.4,
  "oceanCurrentDirection": 110,
  "seaStateDouglas": 3,
  "seaStateLabel": "Slight",
  "forecastDays": 3,
  "forecast": [
    { "date": "2026-08-21", "waveHeightMax": 0.86, "swellWaveHeightMax": 0.86, "wavePeriodMax": 9.35, "waveDirectionDominant": 236 }
  ],
  "source": "Open-Meteo Marine",
  "observedAt": "2026-08-21T11:23:57.296Z",
  "error": null
}

Run via API and CLI

Start a run and wait for it to finish, then read the dataset. Replace <TOKEN> with your Apify API token.

Run synchronously and get dataset items in one call:

curl -X POST "https://api.apify.com/v2/acts/scrapers_lat~marine-wave-swell-forecast-scraper/run-sync-get-dataset-items?token=<TOKEN>" \
  -H "Content-Type: application/json" \
  -d '{"locations":["Nazare, Portugal","Pipeline, Hawaii"],"forecastDays":3}'

Start a run asynchronously:

curl -X POST "https://api.apify.com/v2/acts/scrapers_lat~marine-wave-swell-forecast-scraper/runs?token=<TOKEN>" \
  -H "Content-Type: application/json" \
  -d '{"locations":["33.6,-118.3","21.66,-158.05"],"forecastDays":5}'

Apify CLI:

apify call scrapers_lat/marine-wave-swell-forecast-scraper \
  --input '{"locations":["Nazare, Portugal"],"forecastDays":3,"includeHistory":true}'

Fetch results

Every run writes to a dataset. Fetch items as JSON, CSV, or Excel by changing format:

# JSON
curl "https://api.apify.com/v2/datasets/<DATASET_ID>/items?token=<TOKEN>&clean=true&format=json"

# CSV
curl "https://api.apify.com/v2/datasets/<DATASET_ID>/items?token=<TOKEN>&clean=true&format=csv"

# Paginate large datasets
curl "https://api.apify.com/v2/datasets/<DATASET_ID>/items?token=<TOKEN>&offset=1000&limit=1000"

<DATASET_ID> is returned as defaultDatasetId in the run object. Use offset and limit to page through large result sets. clean=true drops empty and internal fields.

Billing and limits

• Pay per result. You are charged per location returned (result event) plus a small one-time apify-actor-start charge per run. See the pricing tab for current per-event prices.
• Add-ons are opt-in and paid only on success. The 92-day history (marine_history) is charged per location only when a real history series is returned. The AI advisory (ai_marine_advisory) is charged per location only when a usable advisory is produced. Both are off by default and available to paid Apify plans only.
• No charge on failure. If a location cannot be resolved, has no marine data (inland or off-grid), or the run errors, the actor writes a record with a populated error field and does not charge for it. Empty runs cost nothing.
• Spend cap respected. Set maxTotalChargeUsd on the run; once reached, the actor stops emitting and charging further billable results.
• Free Apify plans are capped at 10 locations per run, and the paid add-ons are disabled for them. Upgrade for higher maxResults and add-ons.

FAQ and troubleshooting

A location returned an error about no marine data. Why? Marine conditions are only defined over ocean grid points. If a place name or coordinate resolves to an inland or off-grid point, the actor returns an error record for it and does not charge. Use a coastal or offshore point (a nearby latitude,longitude over water works well).

What is the difference between wave, wind-wave and swell? waveHeight is the total significant wave height. It is decomposed into the windWave component (locally wind-driven chop) and the swell component (longer-period energy that traveled from distant storms). Surfers usually care about the swell height, period and direction.

How is the Douglas sea state computed? seaStateDouglas (0 to 9) is derived from the significant wave height using the standard Douglas scale thresholds, and seaStateLabel gives the matching plain-language label.

Can I pass coordinates instead of a place name? Yes. Any item formatted as latitude,longitude (for example 21.66,-158.05) is used directly, no geocoding. Names are geocoded for convenience and are not charged.

How current is the data? Each record carries observedTime (the local time of the current reading) and observedAt (when the actor collected it). The forecast covers the number of days set in forecastDays.

Is this an official tool? No. This actor is independent and reads only publicly available marine forecast data. It has no affiliation with any weather or ocean agency.

Related scrapers

• Air Quality, AQI, Pollen & UV Scraper: global air quality, US and European AQI, pollutants, pollen and UV.
• Open-Meteo Weather Scraper: global land weather, temperature, precipitation and wind forecast.

More scrapers at scrapers.lat

Built and maintained by scrapers.lat, where we publish scrapers for public platforms: company registries, government data, finance, e-commerce and more. Browse the catalog or request a custom scraper at scrapers.lat.

---

Independent tool, not affiliated with any weather or ocean agency. Accesses only publicly available marine forecast data.