{"skill":{"slug":"marine-forecast","displayName":"Marine Forecast","summary":"Marine and sailing weather via Open-Meteo. Waves, swell, sea temperature, wind, tides, ocean currents, and sailing assessments. Free, no API key, global cove...","description":"---\nname: marine-forecast\ndescription: \"Marine and sailing weather via Open-Meteo. Waves, swell, sea temperature, wind, tides, ocean currents, and sailing assessments. Free, no API key, global coverage.\"\nhomepage: https://open-meteo.com/en/docs/marine-weather-api\nmetadata: {\"clawdbot\":{\"emoji\":\"🌊\",\"requires\":{\"bins\":[\"curl\"]}}}\n---\n\n# Marine Forecast\n\nMarine and sailing weather using Open-Meteo Marine API + Weather API. Free, no API key required, works worldwide.\n\nTwo APIs are used together — replace `LAT`, `LON`, and `TZ` in all commands:\n- **Marine API** (`marine-api.open-meteo.com`) — waves, swell, sea temp, currents, tides\n- **Weather API** (`api.open-meteo.com`) — wind, gusts, air temp, pressure, visibility\n\nFind coordinates for any location using web search or the user's input. Use the nearest timezone (IANA format, e.g. `Europe/London`, `America/New_York`, `Atlantic/Canary`).\n\n## Current conditions\n\nSea state:\n```bash\ncurl -s \"https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&current=wave_height,wave_direction,wave_period,swell_wave_height,swell_wave_direction,swell_wave_period,sea_surface_temperature&timezone=TZ\"\n```\n\nWind and atmosphere:\n```bash\ncurl -s \"https://api.open-meteo.com/v1/forecast?latitude=LAT&longitude=LON&current=temperature_2m,wind_speed_10m,wind_direction_10m,wind_gusts_10m,apparent_temperature,pressure_msl,cloud_cover,visibility&timezone=TZ\"\n```\n\nRun both and combine the results into a single briefing.\n\n## Hourly forecast\n\nMarine (up to 16 days, adjust `forecast_days`):\n```bash\ncurl -s \"https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&hourly=wave_height,wave_direction,wave_period,swell_wave_height,swell_wave_direction,swell_wave_period,swell_wave_peak_period,wind_wave_height,wind_wave_direction,sea_surface_temperature,ocean_current_velocity,ocean_current_direction,sea_level_height_msl&forecast_days=3&timezone=TZ\"\n```\n\nWind (up to 16 days):\n```bash\ncurl -s \"https://api.open-meteo.com/v1/forecast?latitude=LAT&longitude=LON&hourly=wind_speed_10m,wind_direction_10m,wind_gusts_10m,temperature_2m,pressure_msl,visibility,cloud_cover,precipitation_probability&forecast_days=3&timezone=TZ\"\n```\n\n## Daily summary\n\nMarine:\n```bash\ncurl -s \"https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&daily=wave_height_max,wave_direction_dominant,wave_period_max,swell_wave_height_max,swell_wave_direction_dominant,swell_wave_period_max&forecast_days=7&timezone=TZ\"\n```\n\nWeather:\n```bash\ncurl -s \"https://api.open-meteo.com/v1/forecast?latitude=LAT&longitude=LON&daily=wind_speed_10m_max,wind_gusts_10m_max,wind_direction_10m_dominant,temperature_2m_max,temperature_2m_min,sunrise,sunset,uv_index_max,precipitation_probability_max&forecast_days=7&timezone=TZ\"\n```\n\n## Tides (sea level)\n\n```bash\ncurl -s \"https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&hourly=sea_level_height_msl&forecast_days=3&timezone=TZ\"\n```\n\nHigh/low tide: find local maxima and minima in the `sea_level_height_msl` array. Sea level includes tidal signal + inverted barometer effect.\n\n## Ocean currents\n\n```bash\ncurl -s \"https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&hourly=ocean_current_velocity,ocean_current_direction&forecast_days=3&timezone=TZ\"\n```\n\n## Presenting results\n\nAlways present marine data as a structured sailing briefing:\n\n### Current conditions format\n\n```\nSea:    [wave_height]m waves, [wave_period]s period, from [direction]\nSwell:  [swell_wave_height]m from [direction], [swell_wave_period]s period\nWind:   [wind_speed] km/h [direction], gusts [wind_gusts] km/h\nTemp:   Air [temperature]C (feels [apparent_temperature]C), Sea [sea_surface_temperature]C\nSky:    [cloud_cover]% cloud, [visibility/1000]km visibility\n```\n\n### Sailing assessment\n\nRate conditions based on the data:\n- **Calm** — waves < 0.5m, wind < 12 km/h (Beaufort 0-2)\n- **Light** — waves 0.5-1m, wind 12-19 km/h (Beaufort 3)\n- **Moderate** — waves 1-2m, wind 20-38 km/h (Beaufort 4-5)\n- **Rough** — waves 2-3m, wind 39-49 km/h (Beaufort 6)\n- **Very Rough** — waves 3-4m, wind 50-61 km/h (Beaufort 7)\n- **Dangerous** — waves > 4m or wind > 62 km/h (Beaufort 8+)\n\nFlag warnings:\n- Small craft advisory: wind gusts > 50 km/h or wave height > 3m\n- Gale warning: sustained wind > 62 km/h or wave height > 5m\n- Suggest activity suitability: sailing, diving, fishing, swimming, surfing\n\n### Beaufort scale\n\n| Force | km/h | Description | Sea State |\n|-------|------|-------------|-----------|\n| 0 | 0-1 | Calm | Flat |\n| 1 | 2-5 | Light air | Ripples |\n| 2 | 6-11 | Light breeze | Small wavelets |\n| 3 | 12-19 | Gentle breeze | Large wavelets |\n| 4 | 20-28 | Moderate breeze | Small waves |\n| 5 | 29-38 | Fresh breeze | Moderate waves |\n| 6 | 39-49 | Strong breeze | Large waves |\n| 7 | 50-61 | Near gale | Breaking waves |\n| 8 | 62-74 | Gale | High waves |\n| 9 | 75-88 | Severe gale | Very high waves |\n| 10 | 89-102 | Storm | Exceptionally high waves |\n\n### Wind direction conversion\n\nConvert degrees to compass: divide by 22.5, round, index into `[N, NNE, NE, ENE, E, ESE, SE, SSE, S, SSW, SW, WSW, W, WNW, NW, NNW]`.\n\nQuick reference: 0=N, 45=NE, 90=E, 135=SE, 180=S, 225=SW, 270=W, 315=NW.\n\n## Units\n\n| Measurement | Unit |\n|-------------|------|\n| Wave height | meters (m) |\n| Wave period | seconds (s) |\n| Wind speed | km/h |\n| Temperature | Celsius (C) |\n| Current velocity | km/h |\n| Directions | degrees (0=N, 90=E, 180=S, 270=W) |\n| Sea level | meters relative to MSL |\n| Visibility | meters |\n| Pressure | hPa |\n\nUsers may prefer knots for wind. Convert: `knots = km/h * 0.539957`. Add `&wind_speed_unit=kn` to the weather API URL to get knots directly.\n\n## Popular sailing locations (reference)\n\n| Region | Example | Lat | Lon |\n|--------|---------|-----|-----|\n| Canary Islands | Las Palmas | 28.1 | -15.4 |\n| Balearics | Palma de Mallorca | 39.57 | 2.65 |\n| Greek Islands | Piraeus | 37.94 | 23.65 |\n| Croatia | Split | 43.51 | 16.44 |\n| Caribbean | St. Maarten | 18.04 | -63.05 |\n| South Pacific | Tahiti | -17.53 | -149.57 |\n| Southeast Asia | Phuket | 7.88 | 98.39 |\n| East Africa | Zanzibar | -6.16 | 39.19 |\n| Australia | Sydney | -33.87 | 151.21 |\n| US East Coast | Annapolis | 38.97 | -76.49 |\n| UK | Solent | 50.77 | -1.30 |\n| Scandinavia | Gothenburg | 57.71 | 11.97 |\n\n## Data sources\n\n- ECMWF WAM (European Centre for Medium-Range Weather Forecasts)\n- NOAA GFS Wave (Global Forecast System)\n- DWD GWAM/EWAM (German Weather Service)\n- Resolution: 5-25 km depending on region and model\n- Updates: multiple times per day\n- Forecast range: up to 16 days (`forecast_days=16`)\n\n## Notes\n\n- All data is JSON. Parse with `jq` if available, otherwise read raw JSON.\n- Hourly data returns large arrays. For quick checks, use `current` parameters. For planning, use `daily`. Use `hourly` only when the user needs detailed breakdowns.\n- Combine marine + weather API calls to give a complete picture. Neither alone is sufficient for a full sailing briefing.\n- Sea level data approximates tides but does not label high/low explicitly. Derive from local maxima/minima in the hourly array.\n- For coastal areas, data accuracy depends on proximity to the nearest grid point. Open ocean coverage is excellent; harbors and bays may be less precise.\n\nDocs: https://open-meteo.com/en/docs/marine-weather-api\n","tags":{"latest":"1.0.0","marine":"1.0.0","ocean":"1.0.0","sailing":"1.0.0","swell":"1.0.0","tides":"1.0.0","waves":"1.0.0","weather":"1.0.0"},"stats":{"comments":0,"downloads":641,"installsAllTime":2,"installsCurrent":2,"stars":0,"versions":1},"createdAt":1773004500694,"updatedAt":1778491780967},"latestVersion":{"version":"1.0.0","createdAt":1773004500694,"changelog":"Initial release: marine and sailing weather via Open-Meteo. Waves, swell, sea temperature, wind, tides, ocean currents, Beaufort scale, sailing assessments. Free, no API key, global coverage.","license":"MIT-0"},"metadata":{"setup":[],"os":null,"systems":null},"owner":{"handle":"alexissan","userId":"s177nz9wz0wa1w09m3h47wbxk185r2ff","displayName":"Alexis Santos","image":"https://avatars.githubusercontent.com/u/266810?v=4"},"moderation":null}