Marine Forecast

Marine and sailing weather using Open-Meteo Marine API + Weather API. Free, no API key required, works worldwide.

Two APIs are used together — replace LAT, LON, and TZ in all commands:

- Marine API (marine-api.open-meteo.com) — waves, swell, sea temp, currents, tides
Weather API (api.open-meteo.com) — wind, gusts, air temp, pressure, visibility

Find 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).

Current conditions

Sea state:
CODEBLOCK0

Wind and atmosphere:
CODEBLOCK1

Run both and combine the results into a single briefing.

Hourly forecast

Marine (up to 16 days, adjust forecast_days):
CODEBLOCK2

Wind (up to 16 days):
CODEBLOCK3

Daily summary

Marine:
CODEBLOCK4

Weather:
CODEBLOCK5

Tides (sea level)

CODEBLOCK6

High/low tide: find local maxima and minima in the sea_level_height_msl array. Sea level includes tidal signal + inverted barometer effect.

Ocean currents

CODEBLOCK7

Presenting results

Always present marine data as a structured sailing briefing:

Current conditions format

CODEBLOCK8

Sailing assessment

Rate conditions based on the data:

- Calm — waves < 0.5m, wind < 12 km/h (Beaufort 0-2)
Light — waves 0.5-1m, wind 12-19 km/h (Beaufort 3)
Moderate — waves 1-2m, wind 20-38 km/h (Beaufort 4-5)
Rough — waves 2-3m, wind 39-49 km/h (Beaufort 6)
Very Rough — waves 3-4m, wind 50-61 km/h (Beaufort 7)
Dangerous — waves > 4m or wind > 62 km/h (Beaufort 8+)

Flag warnings:

- Small craft advisory: wind gusts > 50 km/h or wave height > 3m
Gale warning: sustained wind > 62 km/h or wave height > 5m
Suggest activity suitability: sailing, diving, fishing, swimming, surfing

Beaufort scale

Force	km/h	Description	Sea State
0	0-1	Calm	Flat
1

2-5 | Light air | Ripples | | 2 | 6-11 | Light breeze | Small wavelets | | 3 | 12-19 | Gentle breeze | Large wavelets | | 4 | 20-28 | Moderate breeze | Small waves | | 5 | 29-38 | Fresh breeze | Moderate waves | | 6 | 39-49 | Strong breeze | Large waves | | 7 | 50-61 | Near gale | Breaking waves | | 8 | 62-74 | Gale | High waves | | 9 | 75-88 | Severe gale | Very high waves | | 10 | 89-102 | Storm | Exceptionally high waves |

Wind direction conversion

Convert 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].

Quick reference: 0=N, 45=NE, 90=E, 135=SE, 180=S, 225=SW, 270=W, 315=NW.

Units

Measurement	Unit
Wave height	meters (m)
Wave period

Users 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.

Popular sailing locations (reference)

Region	Example	Lat	Lon
Canary Islands	Las Palmas	28.1	-15.4
Balearics

Palma de Mallorca | 39.57 | 2.65 | | Greek Islands | Piraeus | 37.94 | 23.65 | | Croatia | Split | 43.51 | 16.44 | | Caribbean | St. Maarten | 18.04 | -63.05 | | South Pacific | Tahiti | -17.53 | -149.57 | | Southeast Asia | Phuket | 7.88 | 98.39 | | East Africa | Zanzibar | -6.16 | 39.19 | | Australia | Sydney | -33.87 | 151.21 | | US East Coast | Annapolis | 38.97 | -76.49 | | UK | Solent | 50.77 | -1.30 | | Scandinavia | Gothenburg | 57.71 | 11.97 |

Data sources

- ECMWF WAM (European Centre for Medium-Range Weather Forecasts)
NOAA GFS Wave (Global Forecast System)
DWD GWAM/EWAM (German Weather Service)
Resolution: 5-25 km depending on region and model
Updates: multiple times per day
Forecast range: up to 16 days (forecast_days=16)

Notes

- All data is JSON. Parse with jq if available, otherwise read raw JSON.
Hourly data returns large arrays. For quick checks, use current parameters. For planning, use daily. Use hourly only when the user needs detailed breakdowns.
Combine marine + weather API calls to give a complete picture. Neither alone is sufficient for a full sailing briefing.
Sea level data approximates tides but does not label high/low explicitly. Derive from local maxima/minima in the hourly array.
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.

Docs: https://open-meteo.com/en/docs/marine-weather-api

海洋预报

使用Open-Meteo海洋API和天气API获取航海和帆船天气。免费，无需API密钥，全球适用。

两个API配合使用——在所有命令中替换LAT、LON和TZ：

- 海洋API（marine-api.open-meteo.com）——海浪、涌浪、海水温度、洋流、潮汐
天气API（api.open-meteo.com）——风、阵风、气温、气压、能见度

通过网络搜索或用户输入获取任意位置的坐标。使用最近的时区（IANA格式，例如Europe/London、America/New_York、Atlantic/Canary）。

当前状况

海况：
bash
curl -s https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON¤t=waveheight,wavedirection,waveperiod,swellwaveheight,swellwavedirection,swellwaveperiod,seasurface_temperature&timezone=TZ

风和大气：
bash
curl -s https://api.open-meteo.com/v1/forecast?latitude=LAT&longitude=LON¤t=temperature2m,windspeed10m,winddirection10m,windgusts10m,apparenttemperature,pressuremsl,cloudcover,visibility&timezone=TZ

运行两者并将结果合并为一份简报。

逐时预报

海洋（最多16天，调整forecast_days）：
bash
curl -s https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&hourly=waveheight,wavedirection,waveperiod,swellwaveheight,swellwavedirection,swellwaveperiod,swellwavepeakperiod,windwaveheight,windwavedirection,seasurfacetemperature,oceancurrentvelocity,oceancurrentdirection,sealevelheightmsl&forecastdays=3&timezone=TZ

风（最多16天）：
bash
curl -s https://api.open-meteo.com/v1/forecast?latitude=LAT&longitude=LON&hourly=windspeed10m,winddirection10m,windgusts10m,temperature2m,pressuremsl,visibility,cloudcover,precipitationprobability&forecast_days=3&timezone=TZ

每日摘要

海洋：
bash
curl -s https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&daily=waveheightmax,wavedirectiondominant,waveperiodmax,swellwaveheightmax,swellwavedirectiondominant,swellwaveperiodmax&forecastdays=7&timezone=TZ

天气：
bash
curl -s https://api.open-meteo.com/v1/forecast?latitude=LAT&longitude=LON&daily=windspeed10mmax,windgusts10mmax,winddirection10mdominant,temperature2mmax,temperature2mmin,sunrise,sunset,uvindexmax,precipitationprobabilitymax&forecastdays=7&timezone=TZ

潮汐（海平面）

bash
curl -s https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&hourly=sealevelheightmsl&forecastdays=3&timezone=TZ

高潮/低潮：在sealevelheight_msl数组中查找局部最大值和最小值。海平面包括潮汐信号和反气压计效应。

洋流

bash
curl -s https://marine-api.open-meteo.com/v1/marine?latitude=LAT&longitude=LON&hourly=oceancurrentvelocity,oceancurrentdirection&forecast_days=3&timezone=TZ

呈现结果

始终以结构化的航海简报形式呈现海洋数据：

当前状况格式

海况： [waveheight]米浪高，[waveperiod]秒周期，来自[direction]方向
涌浪： [swellwaveheight]米来自[direction]方向，[swellwaveperiod]秒周期
风： [windspeed]公里/小时[direction]方向，阵风[windgusts]公里/小时
温度：空气[温度]°C（体感[体感温度]°C），海水[seasurfacetemperature]°C
天空： [cloud_cover]%云量，[visibility/1000]公里能见度

航行评估

根据数据评估状况：

- 平静——浪高<0.5米，风速<12公里/小时（蒲福风级0-2）
轻风——浪高0.5-1米，风速12-19公里/小时（蒲福风级3）
适中——浪高1-2米，风速20-38公里/小时（蒲福风级4-5）
汹涌——浪高2-3米，风速39-49公里/小时（蒲福风级6）
非常汹涌——浪高3-4米，风速50-61公里/小时（蒲福风级7）
危险——浪高>4米或风速>62公里/小时（蒲福风级8+）

警示标志：

- 小型船只预警：阵风>50公里/小时或浪高>3米
大风警报：持续风速>62公里/小时或浪高>5米
建议活动适宜性：帆船、潜水、钓鱼、游泳、冲浪

蒲福风级表

风级	公里/小时	描述	海况
0	0-1	无风	平静
1

2-5 | 软风 | 涟漪 | | 2 | 6-11 | 轻风 | 小波 | | 3 | 12-19 | 微风 | 中波 | | 4 | 20-28 | 和风 | 小浪 | | 5 | 29-38 | 清风 | 中浪 | | 6 | 39-49 | 强风 | 大浪 | | 7 | 50-61 | 疾风 | 碎浪 | | 8 | 62-74 | 大风 | 巨浪 | | 9 | 75-88 | 烈风 | 非常巨浪 | | 10 | 89-102 | 暴风 | 异常巨浪 |

风向转换

将度数转换为罗盘方向：除以22.5，四舍五入，索引到[北, 北北东, 东北, 东北东, 东, 东南东, 东南, 南南东, 南, 南南西, 西南, 西南西, 西, 西北西, 西北, 北北西]。

快速参考：0=北，45=东北，90=东，135=东南，180=南，225=西南，270=西，315=西北。

单位

测量项	单位
浪高	米（m）
浪周期

秒（s） | | 风速 | 公里/小时 | | 温度 | 摄氏度（°C） | | 洋流速度 | 公里/小时 | | 方向 | 度（0=北，90=东，180=南，270=西） | | 海平面 | 相对于平均海平面的米数 | | 能见度 | 米 | | 气压 | 百帕 |

用户可能偏好节作为风速单位。转换：节 = 公里/小时 * 0.539957。在天气API URL中添加&windspeedunit=kn可直接获取节。

区域	示例	纬度	经度
加那利群岛	拉斯帕尔马斯	28.1	-15.4
巴利阿里群岛