The Oceanographic Products and Services Division (OPSD) of the National Oceanic and Atmospheric Administration (NOAA) "collects, analyzes and distributes historical and real-time observations and predictions of water levels, coastal currents and other meteorological and oceanographic data." This wonderful site explains the science behind the tides and changing water levels, gives historical...

Tides Online is a continually updated database of tidal information maintained by NOAA's Center for Operational Oceanographic Products and Services. The site contains data from stations from every coastal state in the US including the Great Lakes. The main page shows which stations are currently under a "storm surge" and contains the links to the individual station data -- of which the easiest to...