WordNet (r) 3.0 (2006):

tidewater
    n 1: low-lying coastal land drained by tidal streams
    2: the coastal plain of the South: eastern parts of Virginia and
       North Carolina and South Carolina and Georgia [syn:
       Tidewater, Tidewater region]

Moby Thesaurus II by Grady Ward, 1.0:

76 Moby Thesaurus words for "tidewater":
   bank, bayed, beach, berm, coast, coastland, coastline, direct tide,
   ebb, ebb and flow, ebb tide, embankment, embayed, estuarine, flood,
   flood tide, flow, fluviomarine, flux, flux and reflux, foreshore,
   full tide, gulfed, gulflike, gulfy, high tide, high water,
   ironbound coast, lido, littoral, low tide, low water, lunar tide,
   neap, neap tide, opposite tide, plage, playa, refluence, reflux,
   rip, riptide, riverside, riviera, rockbound coast, sands,
   sea margin, seabank, seabeach, seaboard, seacliff, seacoast,
   seashore, seaside, shingle, shore, shoreline, solar tide,
   spring tide, strand, submerged coast, thalassometer,
   tidal amplitude, tidal current, tidal current chart, tidal flow,
   tidal range, tide, tide chart, tide gate, tide gauge, tide race,
   tide rip, tideway, waterfront, waterside