Deep water buoy

The Donostia deep-water buoy came into operation in 2007 and is anchored some 12 miles north of the coast in an area with a depth of about 500 m (on the continental slope).

At this depth, not even waves with a period of about 20 seconds (the characteristics of the swell generated by the squalls that cross the northeast Atlantic between Iceland and Ireland) are affected by the seabed, hence the name “deep water buoy”. As the swell approaches the coastline and the depth decreases, the wave shape, height and direction is affected by the thickness of water between the sea surface and the seabed. The wave, on its way from deep water, passes through the intermediate depth zone (where its shape, height and direction are slightly depth-dependent) and the shallow water zone (where its behaviour is strongly depth-dependent), until it breaks against the shore.