How to read the buoy data
Puertos del Estado's coastal buoys measure the state of the sea in real time at the exact point where they're anchored. They're the most reliable source for knowing how the sea is right now.
Wave height (m)
Shows the average height of the waves recorded by the buoy. It's not the height of the biggest wave, but a statistical average of the swell at that moment.
Period (s)
The period is the time between one wave passing and the next. Long periods (10-16 s) usually indicate ground swell with more energy and quality; short periods (under 8 s) are usually local wind swell, which tends to be messier.
Direction (°)
Shows where the swell is coming from, in degrees from north. It's key to knowing whether that direction will reach your usual spot well, or whether it will be blocked by the coastline or a headland.
Real-time data
Unlike maps and tables, which are forecasts, buoy data is measured live, making it the best reference to check whether the forecast is actually holding up.