CDIP Wave Buoys

The Coastal Data Information Program (CDIP) is an extensive network for monitoring waves and beaches along the coastlines of the United States. Waves are a critical factor in all shore processes, playing a central role in everything from stresses on coastal structures to sand transport and beach formation. These moored buoys measure significant wave height, wave period, and the direction of wave propagation.

time period: current; updates every 30 minutes.

source:
http://cdip.ucsd.edu/?nav=documents&sub=faq&xitem=access

info: http://cdip.ucsd.edu