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Île de Batz wave buoy observations on Thu, Dec 4, 2025

Hourly readings from the Île de Batz wave buoy for Thu, Dec 4, 2025, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Oldest observation available

Daily means for

Latest

Period Summary

Programmatically generated summary. Hog Says

48 wave-buoy observations were recorded during the day. Typical wave height was 8.3 ft (10th–90th percentile 7.4–9.2 ft), while mean average of more than one wave period type was 11.7 seconds (10th–90th percentile 9.8–13.1 seconds). Typical calculated wave power was approximately 29.9 kW/m (10th–90th percentile 23.1–34.5 kW/m), derived from significant wave height and energy period. All 143 checked values passed quality control.

Generated only from the observations and comparisons shown on this page.

Line chart showing wave height, wave period and sea temperature for Île de Batz. Use the detailed observations table below for the same data in text form.

About Île de Batz wave buoy

Île de Batz is a CANDHIS directional buoy off northern Brittany, within the French national sea-state observatory coordinated by Cerema. The station sits at the western entrance to the English Channel, where Atlantic swell rounds Brittany towards the exposed Finistère and Channel coasts.

Its current data source reports wave height, wave period, wave direction, directional spread and sea temperature.

Metrics are rows; hours run left to right. Times use your device time zone.
Île de Batz wave buoy hourly observations Thu, Dec 4, 2025Last observation shown
Metric
Significant wave height (ft)787868889989999888788777889101091099889998888788988
Maximum wave height (ft)111111121110121312131414181414121312111311111111131212161614171417151514141411131411111112131412
Peak period (s)121313131112121313131212111212101291310121191010-10101010111111111212131313131413131313141313
Average period (s)111212121111999888899899891089899999999991110101010111112121212131212
Mean period Tm02 (s)99910987666666676776776667-7777777777777788889988
Peak wave directionWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNW-WNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNWWNW
Directional spread (°)23.721.118.218.121.318.522.318.719.721.625.521.724.324.620.327.422.221.025.023.525.426.121.822.321.3-23.519.220.824.121.222.021.318.618.218.723.320.724.022.321.819.222.020.520.115.922.322.4
Water temperature(°C)------------------------------------------------

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Wave metric colour key

Colours move through the scale as each number increases. They do not by themselves mean that conditions are good, safe or suitable for you.

Wave & swell height0–40+ ft
Wave & swell period0–22+ s
Wind speed0–75 mph

The displayed numbers remain the source of truth; colour is an additional visual cue.

What does buoy wave power mean?

kW/m means kilowatts of wave power per metre of wave crest. It describes the rate at which the observed sea state carries energy past the buoy.

Unlike the shore-directed forecast value, buoy wave power is the total power at the observation point. It is not projected towards a particular beach and does not predict breaking wave height.

In deep water, wave power can be calculated with:

P is approximately 0.49 times significant wave height squared times wave energy period.

P is power in kW/m, Hs is significant wave height in metres, and Te is wave energy period in seconds.

  • Provider-reported power is used when available.
  • Otherwise, a value is calculated only when both significant height and a genuine energy period are available. The ≈ symbol marks calculated values.
  • A dash is shown instead of substituting peak, Tm02, zero-crossing or other period measurements.
  • Daily and monthly figures use the mean of hourly-normalized observation power values; they are not calculated from mean height and period.

Wave direction, spectrum, water depth and local bathymetry still matter. Wave power is best read alongside height, period and direction rather than as a standalone surf-quality score.

The observation data displayed on this page is from the Cerema CANDHIS coastal wave observatory.

Learn how SurfHog combines, checks and summarizes observations in the data and methodology notes.

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