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Plateau du Four wave buoy daily means for Nov 2013

Daily means from the Plateau du Four wave buoy for Nov 2013, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Data available:  to 

Monthly means for

Latest

Period Summary

Programmatically generated summary. Hog Says

1,430 wave-buoy observations covered all 30 days. Typical wave height was 3.9 ft (10th–90th percentile 1.9–8.4 ft), while mean average of more than one wave period type was 9.2 seconds (10th–90th percentile 4–12.3 seconds). Typical calculated wave power was approximately 4.5 kW/m (10th–90th percentile 1.2–25.1 kW/m), derived from significant wave height and energy period. 61 of 4,280 checked values (1.4%) were excluded by quality control. Across 3 comparable years, mean wave height was below the same-month mean of 5.3 ft and mean wave period was below the same-month mean of 10 seconds.

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

Typical Significant Wave Height

3.9ft
Mean: 4.7 ft
P10–P90: 1.9 — 8.4 ft
Recorded extremes

0.9 — 13.8 ft

Mean Observed Wave Period

9.2secs
P10–P90: 4 — 12.3secs
Recorded extremes

3.1 — 18.7secs

Available for 705 of 717 hourly samples

Typical Wave Power

Approximately 4.45kW/m
Mean: 10.24kW/m
P10–P90: 1.2 — 25.1kW/m
Recorded extremes

0.25 — 70.39kW/m

Calculated from significant wave height and energy period.

Available for 713 of 717 hourly samples with wave power

Typical Observed Wind

-, -mph
Mean: - mph
P10–P90: - — - mph

Available for 0 of 717 hourly samples

Mean Water Temperature

-°C
P10–P90: - — -°C

Available for 0 of 717 hourly samples

Compared With Previous Novembers

Historical baseline from 3,834 observations across 3 years.

Wave Height
4.7ft
0.6ft below mean
Historical mean 5.315ft
Wave Period
9.2s
0.8s below mean
Historical mean 10s
Water Temperature
–
Not enough comparable data

Chart showing grouped wave observations for Plateau du Four. Use the table on this page for a text version of the same measurements. To open hourly observations, use a linked day name in the table.

About Plateau du Four wave buoy

Plateau du Four is a CANDHIS station associated with the SEM-REV offshore test site off Loire-Atlantique. Located near a shallow offshore bank west of Le Croisic, it supplies environmental context for marine-energy research and for an exposed sector between the Loire estuary and southern Brittany.

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

Metrics are rows; days run left to right.
Plateau du Four wave buoy daily means Nov 2013Last observation shown
Metric
Mean significant wave height (ft)7891088768854344322456333321123
Mean maximum wave height (ft)1113131512121110121277466443689544442234
Mean peak period (s)1398111088881011111278891288595131171012137
Mean average period (s)8889888879888765610566544444585
Mean period Tm02 (s)666766666766655458455444433464
Mean peak wave directionWSWconcentration 93%WSWconcentration 100%WSWconcentration 99%WSWconcentration 100%WSWconcentration 100%WSWconcentration 100%WSWconcentration 99%WSWconcentration 100%WSWconcentration 100%WSWconcentration 100%Wconcentration 100%Wconcentration 100%Wconcentration 93%WNWconcentration 98%NWconcentration 63%NWconcentration 49%WNWconcentration 50%Wconcentration 100%Wconcentration 97%Wconcentration 100%NWconcentration 83%WNWconcentration 64%NNWconcentration 70%WNWconcentration 78%WNWconcentration 78%NNWconcentration 56%Wconcentration 77%Wconcentration 90%Wconcentration 99%NWconcentration 62%
Mean directional spread (°)24.523.123.023.823.424.124.924.124.821.824.722.725.521.427.730.728.523.723.621.826.428.927.128.026.524.427.929.825.927.8
Mean 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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