[Illustration: FIG. 67 FIG. 67--A tidal inlet through the barrier beach south of Beach Haven, N. J., connecting the Atlantic Ocean to the right (east) with Little Egg Harbor to the left. The beach sand south of the inlet is little above water level and is frequently washed by waves, which shift the sand and produce the clouded appearance of the sandy surface. The light-colored ragged belt at the right is surf; the continuous narrow belt, beach sand; the clouded areas, recently washed wet or slightly submerged sand. (The ordinary tidal variation here is 4.2 feet.) This inlet does not appear on the 1914 edition of U. S. Coast and Geodetic Survey Chart 1216, and sand hooks had little more than begun to form then. Scale, about 1:14,000.] [Illustration: FIG. 68. (For explanation see bottom of next page.)] [Illustration: FIG. 68--Beach between Brigantine and Little Egg Inlets, New Jersey, showing a variety of features characteristic of a wave-built sand barrier. The upper (northern) part of the illustration shows several places where waves have broken over the sand barrier and washed the sand westward, where it was redeposited at the left in the quiet, protected water. Farther south are older wash-overs, where the enclosed bay is nearly filled with sand. At the left are numerous islands, streams, and flats characteristic of the salt marshes west of the barrier beach along the New Jersey coast. Scale, about 1:7,000.] [Illustration: FIG. 69--A simple spit: Lower Cedar Point, Maryland, on the left bank of the lower Potomac River, 6 miles north of Colonial Beach, Va., as seen obliquely downward from a height of 4,000 feet. The white line on either side of the point is sand at the foot of bluffs. Houses and fields are seen at the left.] occur along the shore, the water line varies little from year to year. But on very low lands, like those along Chesapeake Bay south of the mouth of York River, shown in Figure 59, the strand may migrate over a broad belt between high and low tide. For this reason it is desirable that photographs of areas affected by the tide be accompanied by a record of the date and time of day at which the exposure was made, in order that the height of the tide at the time of exposure can be computed. As the shore on the Coast and Geodetic Survey charts denotes the water line at high tide, a photograph taken at low tide might be interpreted as indicating an error on the chart. Where the water migrates over such a broad belt of sand or mud, the problems of charting become very troublesome. Photographs of such areas could be taken at both low and high tide, and from these the belt of daily flooding could be charted.