At the 2013 Winter Seminar, Dr. Tony Navoy gave an excellent presentation on water levels in Barnegat Bay.
There are buoys throughout the bay that measure water levels and water temperatures. Locations include the Rt 37 Bridge and Barnegat Inlet. This is real-time data. You can see levels that were recorded within the last hour. Dr. Navoy recommends you correlate the buoy readings to your own observations at various spots in the bay. The pdf below describes how to access the data. In summary:
Go to: http://nj.usgs.gov
Select "Tide" Under Realtime Data on left
Select station of interest from the list
Graph shows last 7 days of water levels
If "most recent instantaneous value" is more than 1 hr old, the guage may be having problems.