intertidal zone. Region between the high tide and the low tide of an area.

Land between the high and low tides that is uncovered each day by tidal action. It belongs to the owner of the land that fronts on the sea at that point. 2) Land that is submerged below the low-tide p [..]

The zone between the mean high water and mean low water lines.  

The zone between the mean high water and mean low water lines. It is identical with intertidal zone (technical definition) when the type of tide is semi diurnal or diurnal.

Tidelands are the beds and shores of navigable tidal waters lying between the line of ordinary high tide and the line of extreme low tide.

All lands and waters between the high water mark and the seaward limit of the Commonwealth's jurisdiction, as defined in 310 CMR 9:04. Tidewaters are synonymous with tidelands.

 The zone between the mean high-water line and the mean low-water line, commonly referred to as the "beach." Waters above the tidelands are inland, being landward of the coast line. Despite the traditional reference to "tidelands litigation," the United States never questioned state jurisdiction over these lands. [..]

Those lands which are daily covered and uncovered by water by the action of the tides, up to the mean line of the ordinary high tides.