Height
0.3m
Hs
Period
3s
Tp
Direction
E
78°
Water
12.2°C
Last update: 23 May, 23:00
Access historical readings and compare readings with the forecast
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Last 24 hours
Time(CDT) | Wave height | Max height | Period | Direction | Water temperature | Energy |
|---|---|---|---|---|---|---|
Buoy GB17 - South Green Bay, WI continuously measures essential oceanographic parameters for surfing and water sports. (44.794000° lat, -87.758000° lng)
This marine station records significant wave height, maximum height, wave period, swell direction, and water temperature.
Data for GB17 - South Green Bay, WI comes from NOAA NDBC. For the United States and many offshore stations, it is a reference source because the NDBC network is built for continuous operational observation and public dissemination of measurements.
The average of the highest third of waves. This is the most representative measure of the wave size you'll see on the water.
The highest wave recorded during the measurement period. Generally 1.5 to 2 times the significant height.
The time in seconds between two wave crests. A long period (>12s) indicates more powerful and consistent groundswell.
The direction the swell is coming from. The impact on the coast depends on the shoreline orientation.
Significant height (Hs) is the average of the highest third of waves, representing what you typically observe. Maximum height (Hmax) is the largest wave measured, often 1.5 to 2 times higher than Hs. A set of large waves can occasionally exceed Hs.
A long period (>12s) means waves have traveled far and carry more energy (groundswell). A short period (<8s) indicates local wind-generated swell, more disorganized. For surfing, longer periods produce more powerful and better-shaped waves.
Buoys typically transmit their data every 30 minutes to 1 hour. The delay between measurement and display depends on the transmission network and our collection system.
The buoy measures direction offshore. Waves change direction as they approach the coast due to refraction (seabed effect). Beach orientation and coastal obstacles also influence the final wave direction.
Height
0.3m
Hs
Period
3s
Tp
Direction
E
78°
Water
12.2°C
Last update: 23 May, 23:00
| May 23, 04:30 PM | 0.4m 3 kJ | - | 3.0s | 80° E | 12.3°C | 3 kJ |
| May 23, 04:00 PM | 0.3m 1 kJ | - | 2.0s | 78° E | 12.4°C | 1 kJ |
| May 23, 03:30 PM | 0.3m 2 kJ | - | 3.0s | 74° E | 12.4°C | 2 kJ |
| May 23, 03:00 PM | 0.3m 1 kJ | - | 2.0s | 75° E | 12.4°C | 1 kJ |
| May 23, 10:00 AM | 0.3m 2 kJ | - | 3.0s | 76° E | 11.7°C | 2 kJ |
| May 23, 09:30 AM | 0.3m 2 kJ | - | 3.0s | 78° E | 11.6°C | 2 kJ |
| May 23, 09:00 AM | 0.3m 2 kJ | - | 3.0s | 81° E | 11.6°C | 2 kJ |
| May 23, 08:30 AM | 0.3m 2 kJ | - | 3.0s | 84° E | 11.6°C | 2 kJ |
| May 23, 08:00 AM | 0.3m 2 kJ | - | 3.0s | 84° E | 11.6°C | 2 kJ |
| May 23, 07:30 AM | 0.3m 2 kJ | - | 3.0s | 81° E | 11.6°C | 2 kJ |