For specific cities, try
the Weather Underground. Coastal cities have links to the Marine Forecast for those areas.
buoys and tides
National Data Buoy Center Buoy Observations Check out what it's doing offshore of your favorite ocean sites. Includes wave and wind information, both current and previous observations.
NWS Tidal Predictor Is it high tide or low tide at your favorite spot? You can also use this program to predict future tides so that trip to Huguenot or Hatteras won't be a washout.